OpenCloudOS-Kernel/sound/usb/line6/pcm.c

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/*
* Line 6 Linux USB driver
*
* Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2.
*
*/
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include "capture.h"
#include "driver.h"
#include "playback.h"
/* impulse response volume controls */
static int snd_line6_impulse_volume_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo)
{
uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
uinfo->count = 1;
uinfo->value.integer.min = 0;
uinfo->value.integer.max = 255;
return 0;
}
static int snd_line6_impulse_volume_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
ucontrol->value.integer.value[0] = line6pcm->impulse_volume;
return 0;
}
static int snd_line6_impulse_volume_put(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
int value = ucontrol->value.integer.value[0];
int err;
if (line6pcm->impulse_volume == value)
return 0;
line6pcm->impulse_volume = value;
if (value > 0) {
err = line6_pcm_acquire(line6pcm, LINE6_STREAM_IMPULSE, true);
if (err < 0) {
line6pcm->impulse_volume = 0;
return err;
}
} else {
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
line6_pcm_release(line6pcm, LINE6_STREAM_IMPULSE);
}
return 1;
}
/* impulse response period controls */
static int snd_line6_impulse_period_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo)
{
uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
uinfo->count = 1;
uinfo->value.integer.min = 0;
uinfo->value.integer.max = 2000;
return 0;
}
static int snd_line6_impulse_period_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
ucontrol->value.integer.value[0] = line6pcm->impulse_period;
return 0;
}
static int snd_line6_impulse_period_put(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
int value = ucontrol->value.integer.value[0];
if (line6pcm->impulse_period == value)
return 0;
line6pcm->impulse_period = value;
return 1;
}
/*
Unlink all currently active URBs.
*/
static void line6_unlink_audio_urbs(struct snd_line6_pcm *line6pcm,
struct line6_pcm_stream *pcms)
{
int i;
for (i = 0; i < line6pcm->line6->iso_buffers; i++) {
if (test_bit(i, &pcms->active_urbs)) {
if (!test_and_set_bit(i, &pcms->unlink_urbs))
usb_unlink_urb(pcms->urbs[i]);
}
}
}
/*
Wait until unlinking of all currently active URBs has been finished.
*/
static void line6_wait_clear_audio_urbs(struct snd_line6_pcm *line6pcm,
struct line6_pcm_stream *pcms)
{
int timeout = HZ;
int i;
int alive;
do {
alive = 0;
for (i = 0; i < line6pcm->line6->iso_buffers; i++) {
if (test_bit(i, &pcms->active_urbs))
alive++;
}
if (!alive)
break;
set_current_state(TASK_UNINTERRUPTIBLE);
schedule_timeout(1);
} while (--timeout > 0);
if (alive)
dev_err(line6pcm->line6->ifcdev,
"timeout: still %d active urbs..\n", alive);
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
static inline struct line6_pcm_stream *
get_stream(struct snd_line6_pcm *line6pcm, int direction)
{
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
return (direction == SNDRV_PCM_STREAM_PLAYBACK) ?
&line6pcm->out : &line6pcm->in;
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
/* allocate a buffer if not opened yet;
* call this in line6pcm.state_mutex
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
*/
static int line6_buffer_acquire(struct snd_line6_pcm *line6pcm,
struct line6_pcm_stream *pstr, int direction, int type)
{
const int pkt_size =
(direction == SNDRV_PCM_STREAM_PLAYBACK) ?
line6pcm->max_packet_size_out :
line6pcm->max_packet_size_in;
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
/* Invoked multiple times in a row so allocate once only */
if (!test_and_set_bit(type, &pstr->opened) && !pstr->buffer) {
pstr->buffer = kmalloc(line6pcm->line6->iso_buffers *
LINE6_ISO_PACKETS * pkt_size, GFP_KERNEL);
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
if (!pstr->buffer)
return -ENOMEM;
}
return 0;
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
/* free a buffer if all streams are closed;
* call this in line6pcm.state_mutex
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
*/
static void line6_buffer_release(struct snd_line6_pcm *line6pcm,
struct line6_pcm_stream *pstr, int type)
{
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
clear_bit(type, &pstr->opened);
if (!pstr->opened) {
line6_wait_clear_audio_urbs(line6pcm, pstr);
kfree(pstr->buffer);
pstr->buffer = NULL;
}
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
/* start a PCM stream */
static int line6_stream_start(struct snd_line6_pcm *line6pcm, int direction,
int type)
{
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
unsigned long flags;
struct line6_pcm_stream *pstr = get_stream(line6pcm, direction);
int ret = 0;
spin_lock_irqsave(&pstr->lock, flags);
if (!test_and_set_bit(type, &pstr->running) &&
!(pstr->active_urbs || pstr->unlink_urbs)) {
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
pstr->count = 0;
/* Submit all currently available URBs */
if (direction == SNDRV_PCM_STREAM_PLAYBACK)
ret = line6_submit_audio_out_all_urbs(line6pcm);
else
ret = line6_submit_audio_in_all_urbs(line6pcm);
staging: line6: separate handling of buffer allocation and stream startup There are several features of the Line6 USB driver which require PCM data to be exchanged with the device: *) PCM playback and capture via ALSA *) software monitoring (for devices without hardware monitoring) *) optional impulse response measurement However, from the device's point of view, there is just a single capture and playback stream, which must be shared between these subsystems. It is therefore necessary to maintain the state of the subsystems with respect to PCM usage. We define several constants of the form LINE6_BIT_PCM_<subsystem>_<direction>_<resource> with the following meanings: *) <subsystem> is one of -) ALSA: PCM playback and capture via ALSA -) MONITOR: software monitoring -) IMPULSE: optional impulse response measurement *) <direction> is one of -) PLAYBACK: audio output (from host to device) -) CAPTURE: audio input (from device to host) *) <resource> is one of -) BUFFER: buffer required by PCM data stream -) STREAM: actual PCM data stream The subsystems call line6_pcm_acquire() to acquire the (shared) resources needed for a particular operation (e.g., allocate the buffer for ALSA playback or start the capture stream for software monitoring). When a resource is no longer needed, it is released by calling line6_pcm_release(). Buffer allocation and stream startup are handled separately to allow the ALSA kernel driver to perform them at appropriate places (since the callback which starts a PCM stream is not allowed to sleep). Signed-off-by: Markus Grabner <grabner@icg.tugraz.at> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-01-20 07:09:09 +08:00
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
if (ret < 0)
clear_bit(type, &pstr->running);
spin_unlock_irqrestore(&pstr->lock, flags);
return ret;
}
staging: line6: separate handling of buffer allocation and stream startup There are several features of the Line6 USB driver which require PCM data to be exchanged with the device: *) PCM playback and capture via ALSA *) software monitoring (for devices without hardware monitoring) *) optional impulse response measurement However, from the device's point of view, there is just a single capture and playback stream, which must be shared between these subsystems. It is therefore necessary to maintain the state of the subsystems with respect to PCM usage. We define several constants of the form LINE6_BIT_PCM_<subsystem>_<direction>_<resource> with the following meanings: *) <subsystem> is one of -) ALSA: PCM playback and capture via ALSA -) MONITOR: software monitoring -) IMPULSE: optional impulse response measurement *) <direction> is one of -) PLAYBACK: audio output (from host to device) -) CAPTURE: audio input (from device to host) *) <resource> is one of -) BUFFER: buffer required by PCM data stream -) STREAM: actual PCM data stream The subsystems call line6_pcm_acquire() to acquire the (shared) resources needed for a particular operation (e.g., allocate the buffer for ALSA playback or start the capture stream for software monitoring). When a resource is no longer needed, it is released by calling line6_pcm_release(). Buffer allocation and stream startup are handled separately to allow the ALSA kernel driver to perform them at appropriate places (since the callback which starts a PCM stream is not allowed to sleep). Signed-off-by: Markus Grabner <grabner@icg.tugraz.at> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-01-20 07:09:09 +08:00
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
/* stop a PCM stream; this doesn't sync with the unlinked URBs */
static void line6_stream_stop(struct snd_line6_pcm *line6pcm, int direction,
int type)
{
unsigned long flags;
struct line6_pcm_stream *pstr = get_stream(line6pcm, direction);
spin_lock_irqsave(&pstr->lock, flags);
clear_bit(type, &pstr->running);
if (!pstr->running) {
ALSA: line6: Give up on the lock while URBs are released. Done, because line6_stream_stop() locks and calls line6_unlink_audio_urbs(), which in turn invokes audio_out_callback(), which tries to lock 2nd time. Fixes: ============================================= [ INFO: possible recursive locking detected ] 4.4.15+ #15 Not tainted --------------------------------------------- mplayer/3591 is trying to acquire lock: (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa27655>] audio_out_callback+0x70/0x110 [snd_usb_line6] but task is already holding lock: (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa26aad>] line6_stream_stop+0x24/0x5c [snd_usb_line6] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&line6pcm->out.lock)->rlock); lock(&(&line6pcm->out.lock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by mplayer/3591: #0: (snd_pcm_link_rwlock){.-.-..}, at: [<bf8d49a7>] snd_pcm_stream_lock+0x1e/0x40 [snd_pcm] #1: (&(&substream->self_group.lock)->rlock){-.-...}, at: [<bf8d49af>] snd_pcm_stream_lock+0x26/0x40 [snd_pcm] #2: (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa26aad>] line6_stream_stop+0x24/0x5c [snd_usb_line6] stack backtrace: CPU: 0 PID: 3591 Comm: mplayer Not tainted 4.4.15+ #15 Hardware name: Generic AM33XX (Flattened Device Tree) [<c0015d85>] (unwind_backtrace) from [<c001253d>] (show_stack+0x11/0x14) [<c001253d>] (show_stack) from [<c02f1bdf>] (dump_stack+0x8b/0xac) [<c02f1bdf>] (dump_stack) from [<c0076f43>] (__lock_acquire+0xc8b/0x1780) [<c0076f43>] (__lock_acquire) from [<c007810d>] (lock_acquire+0x99/0x1c0) [<c007810d>] (lock_acquire) from [<c06171e7>] (_raw_spin_lock_irqsave+0x3f/0x4c) [<c06171e7>] (_raw_spin_lock_irqsave) from [<bfa27655>] (audio_out_callback+0x70/0x110 [snd_usb_line6]) [<bfa27655>] (audio_out_callback [snd_usb_line6]) from [<c04294db>] (__usb_hcd_giveback_urb+0x53/0xd0) [<c04294db>] (__usb_hcd_giveback_urb) from [<c046388d>] (musb_giveback+0x3d/0x98) [<c046388d>] (musb_giveback) from [<c04647f5>] (musb_urb_dequeue+0x6d/0x114) [<c04647f5>] (musb_urb_dequeue) from [<c042ac11>] (usb_hcd_unlink_urb+0x39/0x98) [<c042ac11>] (usb_hcd_unlink_urb) from [<bfa26a87>] (line6_unlink_audio_urbs+0x6a/0x6c [snd_usb_line6]) [<bfa26a87>] (line6_unlink_audio_urbs [snd_usb_line6]) from [<bfa26acb>] (line6_stream_stop+0x42/0x5c [snd_usb_line6]) [<bfa26acb>] (line6_stream_stop [snd_usb_line6]) from [<bfa26fe7>] (snd_line6_trigger+0xb6/0xf4 [snd_usb_line6]) [<bfa26fe7>] (snd_line6_trigger [snd_usb_line6]) from [<bf8d47b7>] (snd_pcm_do_stop+0x36/0x38 [snd_pcm]) [<bf8d47b7>] (snd_pcm_do_stop [snd_pcm]) from [<bf8d462f>] (snd_pcm_action_single+0x22/0x40 [snd_pcm]) [<bf8d462f>] (snd_pcm_action_single [snd_pcm]) from [<bf8d46f9>] (snd_pcm_action+0xac/0xb0 [snd_pcm]) [<bf8d46f9>] (snd_pcm_action [snd_pcm]) from [<bf8d4b61>] (snd_pcm_drop+0x38/0x64 [snd_pcm]) [<bf8d4b61>] (snd_pcm_drop [snd_pcm]) from [<bf8d6233>] (snd_pcm_common_ioctl1+0x7fe/0xbe8 [snd_pcm]) [<bf8d6233>] (snd_pcm_common_ioctl1 [snd_pcm]) from [<bf8d6779>] (snd_pcm_playback_ioctl1+0x15c/0x51c [snd_pcm]) [<bf8d6779>] (snd_pcm_playback_ioctl1 [snd_pcm]) from [<bf8d6b59>] (snd_pcm_playback_ioctl+0x20/0x28 [snd_pcm]) [<bf8d6b59>] (snd_pcm_playback_ioctl [snd_pcm]) from [<c016714b>] (do_vfs_ioctl+0x3af/0x5c8) Fixes: 63e20df1e5b2 ('ALSA: line6: Reorganize PCM stream handling') Cc: <stable@vger.kernel.org> # v4.0+ Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com> Signed-off-by: Andrej Krutak <dev@andree.sk> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-19 05:52:11 +08:00
spin_unlock_irqrestore(&pstr->lock, flags);
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
line6_unlink_audio_urbs(line6pcm, pstr);
ALSA: line6: Give up on the lock while URBs are released. Done, because line6_stream_stop() locks and calls line6_unlink_audio_urbs(), which in turn invokes audio_out_callback(), which tries to lock 2nd time. Fixes: ============================================= [ INFO: possible recursive locking detected ] 4.4.15+ #15 Not tainted --------------------------------------------- mplayer/3591 is trying to acquire lock: (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa27655>] audio_out_callback+0x70/0x110 [snd_usb_line6] but task is already holding lock: (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa26aad>] line6_stream_stop+0x24/0x5c [snd_usb_line6] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&line6pcm->out.lock)->rlock); lock(&(&line6pcm->out.lock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by mplayer/3591: #0: (snd_pcm_link_rwlock){.-.-..}, at: [<bf8d49a7>] snd_pcm_stream_lock+0x1e/0x40 [snd_pcm] #1: (&(&substream->self_group.lock)->rlock){-.-...}, at: [<bf8d49af>] snd_pcm_stream_lock+0x26/0x40 [snd_pcm] #2: (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa26aad>] line6_stream_stop+0x24/0x5c [snd_usb_line6] stack backtrace: CPU: 0 PID: 3591 Comm: mplayer Not tainted 4.4.15+ #15 Hardware name: Generic AM33XX (Flattened Device Tree) [<c0015d85>] (unwind_backtrace) from [<c001253d>] (show_stack+0x11/0x14) [<c001253d>] (show_stack) from [<c02f1bdf>] (dump_stack+0x8b/0xac) [<c02f1bdf>] (dump_stack) from [<c0076f43>] (__lock_acquire+0xc8b/0x1780) [<c0076f43>] (__lock_acquire) from [<c007810d>] (lock_acquire+0x99/0x1c0) [<c007810d>] (lock_acquire) from [<c06171e7>] (_raw_spin_lock_irqsave+0x3f/0x4c) [<c06171e7>] (_raw_spin_lock_irqsave) from [<bfa27655>] (audio_out_callback+0x70/0x110 [snd_usb_line6]) [<bfa27655>] (audio_out_callback [snd_usb_line6]) from [<c04294db>] (__usb_hcd_giveback_urb+0x53/0xd0) [<c04294db>] (__usb_hcd_giveback_urb) from [<c046388d>] (musb_giveback+0x3d/0x98) [<c046388d>] (musb_giveback) from [<c04647f5>] (musb_urb_dequeue+0x6d/0x114) [<c04647f5>] (musb_urb_dequeue) from [<c042ac11>] (usb_hcd_unlink_urb+0x39/0x98) [<c042ac11>] (usb_hcd_unlink_urb) from [<bfa26a87>] (line6_unlink_audio_urbs+0x6a/0x6c [snd_usb_line6]) [<bfa26a87>] (line6_unlink_audio_urbs [snd_usb_line6]) from [<bfa26acb>] (line6_stream_stop+0x42/0x5c [snd_usb_line6]) [<bfa26acb>] (line6_stream_stop [snd_usb_line6]) from [<bfa26fe7>] (snd_line6_trigger+0xb6/0xf4 [snd_usb_line6]) [<bfa26fe7>] (snd_line6_trigger [snd_usb_line6]) from [<bf8d47b7>] (snd_pcm_do_stop+0x36/0x38 [snd_pcm]) [<bf8d47b7>] (snd_pcm_do_stop [snd_pcm]) from [<bf8d462f>] (snd_pcm_action_single+0x22/0x40 [snd_pcm]) [<bf8d462f>] (snd_pcm_action_single [snd_pcm]) from [<bf8d46f9>] (snd_pcm_action+0xac/0xb0 [snd_pcm]) [<bf8d46f9>] (snd_pcm_action [snd_pcm]) from [<bf8d4b61>] (snd_pcm_drop+0x38/0x64 [snd_pcm]) [<bf8d4b61>] (snd_pcm_drop [snd_pcm]) from [<bf8d6233>] (snd_pcm_common_ioctl1+0x7fe/0xbe8 [snd_pcm]) [<bf8d6233>] (snd_pcm_common_ioctl1 [snd_pcm]) from [<bf8d6779>] (snd_pcm_playback_ioctl1+0x15c/0x51c [snd_pcm]) [<bf8d6779>] (snd_pcm_playback_ioctl1 [snd_pcm]) from [<bf8d6b59>] (snd_pcm_playback_ioctl+0x20/0x28 [snd_pcm]) [<bf8d6b59>] (snd_pcm_playback_ioctl [snd_pcm]) from [<c016714b>] (do_vfs_ioctl+0x3af/0x5c8) Fixes: 63e20df1e5b2 ('ALSA: line6: Reorganize PCM stream handling') Cc: <stable@vger.kernel.org> # v4.0+ Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com> Signed-off-by: Andrej Krutak <dev@andree.sk> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-19 05:52:11 +08:00
spin_lock_irqsave(&pstr->lock, flags);
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
if (direction == SNDRV_PCM_STREAM_CAPTURE) {
line6pcm->prev_fbuf = NULL;
line6pcm->prev_fsize = 0;
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
}
spin_unlock_irqrestore(&pstr->lock, flags);
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
/* common PCM trigger callback */
int snd_line6_trigger(struct snd_pcm_substream *substream, int cmd)
{
struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
struct snd_pcm_substream *s;
int err;
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
clear_bit(LINE6_FLAG_PREPARED, &line6pcm->flags);
staging: line6: separate handling of buffer allocation and stream startup There are several features of the Line6 USB driver which require PCM data to be exchanged with the device: *) PCM playback and capture via ALSA *) software monitoring (for devices without hardware monitoring) *) optional impulse response measurement However, from the device's point of view, there is just a single capture and playback stream, which must be shared between these subsystems. It is therefore necessary to maintain the state of the subsystems with respect to PCM usage. We define several constants of the form LINE6_BIT_PCM_<subsystem>_<direction>_<resource> with the following meanings: *) <subsystem> is one of -) ALSA: PCM playback and capture via ALSA -) MONITOR: software monitoring -) IMPULSE: optional impulse response measurement *) <direction> is one of -) PLAYBACK: audio output (from host to device) -) CAPTURE: audio input (from device to host) *) <resource> is one of -) BUFFER: buffer required by PCM data stream -) STREAM: actual PCM data stream The subsystems call line6_pcm_acquire() to acquire the (shared) resources needed for a particular operation (e.g., allocate the buffer for ALSA playback or start the capture stream for software monitoring). When a resource is no longer needed, it is released by calling line6_pcm_release(). Buffer allocation and stream startup are handled separately to allow the ALSA kernel driver to perform them at appropriate places (since the callback which starts a PCM stream is not allowed to sleep). Signed-off-by: Markus Grabner <grabner@icg.tugraz.at> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-01-20 07:09:09 +08:00
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
snd_pcm_group_for_each_entry(s, substream) {
if (s->pcm->card != substream->pcm->card)
continue;
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_RESUME:
if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
(line6pcm->line6->properties->capabilities &
LINE6_CAP_IN_NEEDS_OUT)) {
err = line6_stream_start(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
LINE6_STREAM_CAPTURE_HELPER);
if (err < 0)
return err;
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
err = line6_stream_start(line6pcm, s->stream,
LINE6_STREAM_PCM);
if (err < 0)
return err;
break;
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
case SNDRV_PCM_TRIGGER_STOP:
case SNDRV_PCM_TRIGGER_SUSPEND:
if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
(line6pcm->line6->properties->capabilities &
LINE6_CAP_IN_NEEDS_OUT)) {
line6_stream_stop(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
LINE6_STREAM_CAPTURE_HELPER);
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
line6_stream_stop(line6pcm, s->stream,
LINE6_STREAM_PCM);
break;
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
return -EINVAL;
set_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags);
break;
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
return -EINVAL;
clear_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags);
break;
staging: line6: separate handling of buffer allocation and stream startup There are several features of the Line6 USB driver which require PCM data to be exchanged with the device: *) PCM playback and capture via ALSA *) software monitoring (for devices without hardware monitoring) *) optional impulse response measurement However, from the device's point of view, there is just a single capture and playback stream, which must be shared between these subsystems. It is therefore necessary to maintain the state of the subsystems with respect to PCM usage. We define several constants of the form LINE6_BIT_PCM_<subsystem>_<direction>_<resource> with the following meanings: *) <subsystem> is one of -) ALSA: PCM playback and capture via ALSA -) MONITOR: software monitoring -) IMPULSE: optional impulse response measurement *) <direction> is one of -) PLAYBACK: audio output (from host to device) -) CAPTURE: audio input (from device to host) *) <resource> is one of -) BUFFER: buffer required by PCM data stream -) STREAM: actual PCM data stream The subsystems call line6_pcm_acquire() to acquire the (shared) resources needed for a particular operation (e.g., allocate the buffer for ALSA playback or start the capture stream for software monitoring). When a resource is no longer needed, it is released by calling line6_pcm_release(). Buffer allocation and stream startup are handled separately to allow the ALSA kernel driver to perform them at appropriate places (since the callback which starts a PCM stream is not allowed to sleep). Signed-off-by: Markus Grabner <grabner@icg.tugraz.at> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-01-20 07:09:09 +08:00
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
default:
return -EINVAL;
}
}
return 0;
}
/* common PCM pointer callback */
snd_pcm_uframes_t snd_line6_pointer(struct snd_pcm_substream *substream)
{
struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
return pstr->pos_done;
}
/* Acquire and optionally start duplex streams:
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
* type is either LINE6_STREAM_IMPULSE or LINE6_STREAM_MONITOR
*/
int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int type, bool start)
{
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
struct line6_pcm_stream *pstr;
int ret = 0, dir;
/* TODO: We should assert SNDRV_PCM_STREAM_PLAYBACK/CAPTURE == 0/1 */
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
mutex_lock(&line6pcm->state_mutex);
for (dir = 0; dir < 2; dir++) {
pstr = get_stream(line6pcm, dir);
ret = line6_buffer_acquire(line6pcm, pstr, dir, type);
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
if (ret < 0)
goto error;
if (!pstr->running)
line6_wait_clear_audio_urbs(line6pcm, pstr);
}
if (start) {
for (dir = 0; dir < 2; dir++) {
ret = line6_stream_start(line6pcm, dir, type);
if (ret < 0)
goto error;
}
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
error:
mutex_unlock(&line6pcm->state_mutex);
if (ret < 0)
line6_pcm_release(line6pcm, type);
return ret;
}
EXPORT_SYMBOL_GPL(line6_pcm_acquire);
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
/* Stop and release duplex streams */
void line6_pcm_release(struct snd_line6_pcm *line6pcm, int type)
{
struct line6_pcm_stream *pstr;
int dir;
mutex_lock(&line6pcm->state_mutex);
for (dir = 0; dir < 2; dir++)
line6_stream_stop(line6pcm, dir, type);
for (dir = 0; dir < 2; dir++) {
pstr = get_stream(line6pcm, dir);
line6_buffer_release(line6pcm, pstr, type);
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
mutex_unlock(&line6pcm->state_mutex);
}
EXPORT_SYMBOL_GPL(line6_pcm_release);
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
/* common PCM hw_params callback */
int snd_line6_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *hw_params)
{
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
int ret;
struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
mutex_lock(&line6pcm->state_mutex);
ret = line6_buffer_acquire(line6pcm, pstr, substream->stream,
LINE6_STREAM_PCM);
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
if (ret < 0)
goto error;
ret = snd_pcm_lib_malloc_pages(substream,
params_buffer_bytes(hw_params));
if (ret < 0) {
line6_buffer_release(line6pcm, pstr, LINE6_STREAM_PCM);
goto error;
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
pstr->period = params_period_bytes(hw_params);
error:
mutex_unlock(&line6pcm->state_mutex);
return ret;
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
/* common PCM hw_free callback */
int snd_line6_hw_free(struct snd_pcm_substream *substream)
{
struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
mutex_lock(&line6pcm->state_mutex);
line6_buffer_release(line6pcm, pstr, LINE6_STREAM_PCM);
mutex_unlock(&line6pcm->state_mutex);
return snd_pcm_lib_free_pages(substream);
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
/* control info callback */
static int snd_line6_control_playback_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo)
{
uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
uinfo->count = 2;
uinfo->value.integer.min = 0;
uinfo->value.integer.max = 256;
return 0;
}
/* control get callback */
static int snd_line6_control_playback_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
int i;
struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
for (i = 0; i < 2; i++)
ucontrol->value.integer.value[i] = line6pcm->volume_playback[i];
return 0;
}
/* control put callback */
static int snd_line6_control_playback_put(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
int i, changed = 0;
struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
for (i = 0; i < 2; i++)
if (line6pcm->volume_playback[i] !=
ucontrol->value.integer.value[i]) {
line6pcm->volume_playback[i] =
ucontrol->value.integer.value[i];
changed = 1;
}
return changed;
}
/* control definition */
static const struct snd_kcontrol_new line6_controls[] = {
{
.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
.name = "PCM Playback Volume",
.info = snd_line6_control_playback_info,
.get = snd_line6_control_playback_get,
.put = snd_line6_control_playback_put
},
{
.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
.name = "Impulse Response Volume",
.info = snd_line6_impulse_volume_info,
.get = snd_line6_impulse_volume_get,
.put = snd_line6_impulse_volume_put
},
{
.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
.name = "Impulse Response Period",
.info = snd_line6_impulse_period_info,
.get = snd_line6_impulse_period_get,
.put = snd_line6_impulse_period_put
},
};
/*
Cleanup the PCM device.
*/
static void cleanup_urbs(struct line6_pcm_stream *pcms, int iso_buffers)
{
int i;
/* Most likely impossible in current code... */
if (pcms->urbs == NULL)
return;
for (i = 0; i < iso_buffers; i++) {
if (pcms->urbs[i]) {
usb_kill_urb(pcms->urbs[i]);
usb_free_urb(pcms->urbs[i]);
}
}
kfree(pcms->urbs);
pcms->urbs = NULL;
}
static void line6_cleanup_pcm(struct snd_pcm *pcm)
{
struct snd_line6_pcm *line6pcm = snd_pcm_chip(pcm);
cleanup_urbs(&line6pcm->out, line6pcm->line6->iso_buffers);
cleanup_urbs(&line6pcm->in, line6pcm->line6->iso_buffers);
kfree(line6pcm);
}
/* create a PCM device */
static int snd_line6_new_pcm(struct usb_line6 *line6, struct snd_pcm **pcm_ret)
{
struct snd_pcm *pcm;
int err;
err = snd_pcm_new(line6->card, (char *)line6->properties->name,
0, 1, 1, pcm_ret);
if (err < 0)
return err;
pcm = *pcm_ret;
strcpy(pcm->name, line6->properties->name);
/* set operators */
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
&snd_line6_playback_ops);
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_line6_capture_ops);
/* pre-allocation of buffers */
snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
snd_dma_continuous_data
(GFP_KERNEL), 64 * 1024,
128 * 1024);
return 0;
}
/*
Sync with PCM stream stops.
*/
void line6_pcm_disconnect(struct snd_line6_pcm *line6pcm)
{
line6_unlink_audio_urbs(line6pcm, &line6pcm->out);
line6_unlink_audio_urbs(line6pcm, &line6pcm->in);
line6_wait_clear_audio_urbs(line6pcm, &line6pcm->out);
line6_wait_clear_audio_urbs(line6pcm, &line6pcm->in);
}
/*
Create and register the PCM device and mixer entries.
Create URBs for playback and capture.
*/
int line6_init_pcm(struct usb_line6 *line6,
struct line6_pcm_properties *properties)
{
int i, err;
unsigned ep_read = line6->properties->ep_audio_r;
unsigned ep_write = line6->properties->ep_audio_w;
struct snd_pcm *pcm;
struct snd_line6_pcm *line6pcm;
if (!(line6->properties->capabilities & LINE6_CAP_PCM))
return 0; /* skip PCM initialization and report success */
err = snd_line6_new_pcm(line6, &pcm);
if (err < 0)
return err;
line6pcm = kzalloc(sizeof(*line6pcm), GFP_KERNEL);
if (!line6pcm)
return -ENOMEM;
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
mutex_init(&line6pcm->state_mutex);
line6pcm->pcm = pcm;
line6pcm->properties = properties;
line6pcm->volume_playback[0] = line6pcm->volume_playback[1] = 255;
line6pcm->volume_monitor = 255;
line6pcm->line6 = line6;
line6pcm->max_packet_size_in =
usb_maxpacket(line6->usbdev,
usb_rcvisocpipe(line6->usbdev, ep_read), 0);
line6pcm->max_packet_size_out =
usb_maxpacket(line6->usbdev,
usb_sndisocpipe(line6->usbdev, ep_write), 1);
spin_lock_init(&line6pcm->out.lock);
spin_lock_init(&line6pcm->in.lock);
line6pcm->impulse_period = LINE6_IMPULSE_DEFAULT_PERIOD;
line6->line6pcm = line6pcm;
pcm->private_data = line6pcm;
pcm->private_free = line6_cleanup_pcm;
err = line6_create_audio_out_urbs(line6pcm);
if (err < 0)
return err;
err = line6_create_audio_in_urbs(line6pcm);
if (err < 0)
return err;
/* mixer: */
for (i = 0; i < ARRAY_SIZE(line6_controls); i++) {
err = snd_ctl_add(line6->card,
snd_ctl_new1(&line6_controls[i], line6pcm));
if (err < 0)
return err;
}
return 0;
}
EXPORT_SYMBOL_GPL(line6_init_pcm);
/* prepare pcm callback */
int snd_line6_prepare(struct snd_pcm_substream *substream)
{
struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
mutex_lock(&line6pcm->state_mutex);
if (!pstr->running)
line6_wait_clear_audio_urbs(line6pcm, pstr);
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
if (!test_and_set_bit(LINE6_FLAG_PREPARED, &line6pcm->flags)) {
line6pcm->out.count = 0;
line6pcm->out.pos = 0;
line6pcm->out.pos_done = 0;
line6pcm->out.bytes = 0;
line6pcm->in.count = 0;
line6pcm->in.pos_done = 0;
line6pcm->in.bytes = 0;
}
ALSA: line6: Reorganize PCM stream handling The current code deals with the stream start / stop solely via line6_pcm_acquire() and line6_pcm_release(). This was (supposedly) intended to avoid the races, but it doesn't work as expected. The concurrent acquire and release calls can be performed without proper protections, thus this might result in memory corruption. Furthermore, we can't take a mutex to protect the whole function because it can be called from the PCM trigger callback that is an atomic context. Also spinlock isn't appropriate because the function allocates with kmalloc with GFP_KERNEL. That is, these function just lead to singular problems. This is an attempt to reduce the existing races. First off, separate both the stream buffer management and the stream URB management. The former is protected via a newly introduced state_mutex while the latter is protected via each line6_pcm_stream lock. Secondly, the stream state are now managed in opened and running bit flags of each line6_pcm_stream. Not only this a bit clearer than previous combined bit flags, this also gives a better abstraction. These rewrites allows us to make common hw_params and hw_free callbacks for both playback and capture directions. For the monitor and impulse operations, still line6_pcm_acquire() and line6_pcm_release() are used. They call internally the corresponding functions for both playback and capture streams with proper lock or mutex. Unlike the previous versions, these function don't take the bit masks but the only single type value. Also they are supposed to be applied only as duplex operations. Tested-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-27 22:24:09 +08:00
mutex_unlock(&line6pcm->state_mutex);
return 0;
}