OpenCloudOS-Kernel/sound/core/init.c

1185 lines
31 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Initialization routines
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*/
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/ctype.h>
#include <linux/pm.h>
ALSA: jack: implement software jack injection via debugfs This change adds audio jack injection feature through debugfs, with this feature, we could validate alsa userspace changes by injecting plugin or plugout events to the non-phantom audio jacks. With this change, the sound core will build the folders $debugfs_mount_dir/sound/cardN if SND_DEBUG and DEBUG_FS are enabled. And if users also enable the SND_JACK_INJECTION_DEBUG, the jack injection nodes will be built in the folder cardN like below: $tree $debugfs_mount_dir/sound $debugfs_mount_dir/sound ├── card0 │   ├── HDMI_DP_pcm_10_Jack │   │   ├── jackin_inject │   │   ├── kctl_id │   │   ├── mask_bits │   │   ├── status │   │   ├── sw_inject_enable │   │   └── type ... │   └── HDMI_DP_pcm_9_Jack │   ├── jackin_inject │   ├── kctl_id │   ├── mask_bits │   ├── status │   ├── sw_inject_enable │   └── type └── card1 ├── HDMI_DP_pcm_5_Jack │   ├── jackin_inject │   ├── kctl_id │   ├── mask_bits │   ├── status │   ├── sw_inject_enable │   └── type ... ├── Headphone_Jack │   ├── jackin_inject │   ├── kctl_id │   ├── mask_bits │   ├── status │   ├── sw_inject_enable │   └── type └── Headset_Mic_Jack ├── jackin_inject ├── kctl_id ├── mask_bits ├── status ├── sw_inject_enable └── type The nodes kctl_id, mask_bits, status and type are read-only, users could check jack or jack_kctl's information through them. The nodes sw_inject_enable and jackin_inject are directly used for injection. The sw_inject_enable is read-write, users could check if software injection is enabled or not on this jack, and users could echo 1 or 0 to enable or disable software injection on this jack. Once the injection is enabled, the jack will not change by hardware events anymore, once the injection is disabled, the jack will restore the last reported hardware events to the jack. The jackin_inject is write-only, if the injection is enabled, users could echo 1 or 0 to this node to inject plugin or plugout events to this jack. For the detailed usage information on these nodes, please refer to Documentation/sound/designs/jack-injection.rst. Reviewed-by: Takashi Iwai <tiwai@suse.de> Reviewed-by: Jaroslav Kysela <perex@perex.cz> Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Signed-off-by: Hui Wang <hui.wang@canonical.com> Link: https://lore.kernel.org/r/20210127085639.74954-2-hui.wang@canonical.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-01-27 16:56:39 +08:00
#include <linux/debugfs.h>
#include <linux/completion.h>
#include <linux/interrupt.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/info.h>
/* monitor files for graceful shutdown (hotplug) */
struct snd_monitor_file {
struct file *file;
const struct file_operations *disconnected_f_op;
struct list_head shutdown_list; /* still need to shutdown */
struct list_head list; /* link of monitor files */
};
static DEFINE_SPINLOCK(shutdown_lock);
static LIST_HEAD(shutdown_files);
static const struct file_operations snd_shutdown_f_ops;
/* locked for registering/using */
static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
static struct snd_card *snd_cards[SNDRV_CARDS];
static DEFINE_MUTEX(snd_card_mutex);
static char *slots[SNDRV_CARDS];
module_param_array(slots, charp, NULL, 0444);
MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
/* return non-zero if the given index is reserved for the given
* module via slots option
*/
static int module_slot_match(struct module *module, int idx)
{
int match = 1;
#ifdef MODULE
const char *s1, *s2;
if (!module || !*module->name || !slots[idx])
return 0;
s1 = module->name;
s2 = slots[idx];
if (*s2 == '!') {
match = 0; /* negative match */
s2++;
}
/* compare module name strings
* hyphens are handled as equivalent with underscore
*/
for (;;) {
char c1 = *s1++;
char c2 = *s2++;
if (c1 == '-')
c1 = '_';
if (c2 == '-')
c2 = '_';
if (c1 != c2)
return !match;
if (!c1)
break;
}
#endif /* MODULE */
return match;
}
#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
#endif
static int check_empty_slot(struct module *module, int slot)
{
return !slots[slot] || !*slots[slot];
}
/* return an empty slot number (>= 0) found in the given bitmask @mask.
* @mask == -1 == 0xffffffff means: take any free slot up to 32
* when no slot is available, return the original @mask as is.
*/
static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
struct module *module)
{
int slot;
for (slot = 0; slot < SNDRV_CARDS; slot++) {
if (slot < 32 && !(mask & (1U << slot)))
continue;
if (!test_bit(slot, snd_cards_lock)) {
if (check(module, slot))
return slot; /* found */
}
}
return mask; /* unchanged */
}
/* the default release callback set in snd_device_initialize() below;
* this is just NOP for now, as almost all jobs are already done in
* dev_free callback of snd_device chain instead.
*/
static void default_release(struct device *dev)
{
}
/**
* snd_device_initialize - Initialize struct device for sound devices
* @dev: device to initialize
* @card: card to assign, optional
*/
void snd_device_initialize(struct device *dev, struct snd_card *card)
{
device_initialize(dev);
if (card)
dev->parent = &card->card_dev;
dev->class = sound_class;
dev->release = default_release;
}
EXPORT_SYMBOL_GPL(snd_device_initialize);
2021-07-15 15:58:24 +08:00
static int snd_card_init(struct snd_card *card, struct device *parent,
int idx, const char *xid, struct module *module,
size_t extra_size);
static int snd_card_do_free(struct snd_card *card);
static const struct attribute_group card_dev_attr_group;
static void release_card_device(struct device *dev)
{
snd_card_do_free(dev_to_snd_card(dev));
}
/**
* snd_card_new - create and initialize a soundcard structure
* @parent: the parent device object
* @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
* @xid: card identification (ASCII string)
* @module: top level module for locking
* @extra_size: allocate this extra size after the main soundcard structure
* @card_ret: the pointer to store the created card instance
*
* The function allocates snd_card instance via kzalloc with the given
* space for the driver to use freely. The allocated struct is stored
* in the given card_ret pointer.
*
* Return: Zero if successful or a negative error code.
*/
int snd_card_new(struct device *parent, int idx, const char *xid,
struct module *module, int extra_size,
struct snd_card **card_ret)
{
struct snd_card *card;
int err;
if (snd_BUG_ON(!card_ret))
return -EINVAL;
*card_ret = NULL;
if (extra_size < 0)
extra_size = 0;
card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
if (!card)
return -ENOMEM;
2021-07-15 15:58:24 +08:00
err = snd_card_init(card, parent, idx, xid, module, extra_size);
if (err < 0)
return err; /* card is freed by error handler */
2021-07-15 15:58:24 +08:00
*card_ret = card;
return 0;
}
EXPORT_SYMBOL(snd_card_new);
static void __snd_card_release(struct device *dev, void *data)
{
snd_card_free(data);
}
/**
* snd_devm_card_new - managed snd_card object creation
* @parent: the parent device object
* @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
* @xid: card identification (ASCII string)
* @module: top level module for locking
* @extra_size: allocate this extra size after the main soundcard structure
* @card_ret: the pointer to store the created card instance
*
* This function works like snd_card_new() but manages the allocated resource
* via devres, i.e. you don't need to free explicitly.
*
* When a snd_card object is created with this function and registered via
* snd_card_register(), the very first devres action to call snd_card_free()
* is added automatically. In that way, the resource disconnection is assured
* at first, then released in the expected order.
*
* If an error happens at the probe before snd_card_register() is called and
* there have been other devres resources, you'd need to free the card manually
* via snd_card_free() call in the error; otherwise it may lead to UAF due to
* devres call orders. You can use snd_card_free_on_error() helper for
* handling it more easily.
*
* Return: zero if successful, or a negative error code
2021-07-15 15:58:24 +08:00
*/
int snd_devm_card_new(struct device *parent, int idx, const char *xid,
struct module *module, size_t extra_size,
struct snd_card **card_ret)
{
struct snd_card *card;
int err;
*card_ret = NULL;
card = devres_alloc(__snd_card_release, sizeof(*card) + extra_size,
GFP_KERNEL);
if (!card)
return -ENOMEM;
card->managed = true;
err = snd_card_init(card, parent, idx, xid, module, extra_size);
if (err < 0) {
devres_free(card); /* in managed mode, we need to free manually */
2021-07-15 15:58:24 +08:00
return err;
}
devres_add(parent, card);
*card_ret = card;
return 0;
}
EXPORT_SYMBOL_GPL(snd_devm_card_new);
/**
* snd_card_free_on_error - a small helper for handling devm probe errors
* @dev: the managed device object
* @ret: the return code from the probe callback
*
* This function handles the explicit snd_card_free() call at the error from
* the probe callback. It's just a small helper for simplifying the error
* handling with the managed devices.
*
* Return: zero if successful, or a negative error code
*/
int snd_card_free_on_error(struct device *dev, int ret)
{
struct snd_card *card;
if (!ret)
return 0;
card = devres_find(dev, __snd_card_release, NULL, NULL);
if (card)
snd_card_free(card);
return ret;
}
EXPORT_SYMBOL_GPL(snd_card_free_on_error);
2021-07-15 15:58:24 +08:00
static int snd_card_init(struct snd_card *card, struct device *parent,
int idx, const char *xid, struct module *module,
size_t extra_size)
{
int err;
#ifdef CONFIG_SND_DEBUG
char name[8];
#endif
if (extra_size > 0)
card->private_data = (char *)card + sizeof(struct snd_card);
if (xid)
strscpy(card->id, xid, sizeof(card->id));
err = 0;
mutex_lock(&snd_card_mutex);
if (idx < 0) /* first check the matching module-name slot */
idx = get_slot_from_bitmask(idx, module_slot_match, module);
if (idx < 0) /* if not matched, assign an empty slot */
idx = get_slot_from_bitmask(idx, check_empty_slot, module);
if (idx < 0)
err = -ENODEV;
else if (idx < snd_ecards_limit) {
if (test_bit(idx, snd_cards_lock))
err = -EBUSY; /* invalid */
} else if (idx >= SNDRV_CARDS)
err = -ENODEV;
if (err < 0) {
mutex_unlock(&snd_card_mutex);
dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
idx, snd_ecards_limit - 1, err);
if (!card->managed)
kfree(card); /* manually free here, as no destructor called */
return err;
}
set_bit(idx, snd_cards_lock); /* lock it */
if (idx >= snd_ecards_limit)
snd_ecards_limit = idx + 1; /* increase the limit */
mutex_unlock(&snd_card_mutex);
card->dev = parent;
card->number = idx;
#ifdef MODULE
WARN_ON(!module);
card->module = module;
#endif
INIT_LIST_HEAD(&card->devices);
init_rwsem(&card->controls_rwsem);
rwlock_init(&card->ctl_files_rwlock);
INIT_LIST_HEAD(&card->controls);
INIT_LIST_HEAD(&card->ctl_files);
ALSA: control: Use xarray for faster lookups The control elements are managed in a single linked list and we traverse the whole list for matching each numid or ctl id per every inquiry of a control element. This is OK-ish for a small number of elements but obviously it doesn't scale. Especially the matching with the ctl id takes time because it checks each field of the snd_ctl_id element, e.g. the name string is matched with strcmp(). This patch adds the hash tables with Xarray for improving the lookup speed of a control element. There are two xarray tables added to the card; one for numid and another for ctl id. For the numid, we use the numid as the index, while for the ctl id, we calculate a hash key. The lookup is done via a single xa_load() execution. As long as the given control element is found on the Xarray table, that's fine, we can give back a quick lookup result. The problem is when no entry hits on the table, and for this case, we have a slight optimization. Namely, the driver checks whether we had a collision on Xarray table, and do a fallback search (linear lookup of the full entries) only if a hash key collision happened beforehand. So, in theory, the inquiry for a non-existing element might take still time even with this patch in a worst case, but this must be pretty rare. The feature is enabled via CONFIG_SND_CTL_FAST_LOOKUP, which is turned on as default. For simplicity, the option can be turned off only when CONFIG_EXPERT is set ("You are expert? Then you manage 1000 knobs"). Link: https://lore.kernel.org/r/20211028130027.18764-1-tiwai@suse.de Link: https://lore.kernel.org/r/20220609180504.775-1-tiwai@suse.de Link: https://lore.kernel.org/all/cover.1653813866.git.quic_rbankapu@quicinc.com/ Link: https://lore.kernel.org/r/20220610064537.18660-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-06-10 14:45:37 +08:00
#ifdef CONFIG_SND_CTL_FAST_LOOKUP
xa_init(&card->ctl_numids);
xa_init(&card->ctl_hash);
#endif
spin_lock_init(&card->files_lock);
INIT_LIST_HEAD(&card->files_list);
mutex_init(&card->memory_mutex);
#ifdef CONFIG_PM
init_waitqueue_head(&card->power_sleep);
ALSA: control: Track in-flight control read/write/tlv accesses Although the power state check is performed in various places (e.g. at the entrance of quite a few ioctls), there can be still some pending tasks that already went into the ioctl handler or other ops, and those may access the hardware even after the power state check. For example, kcontrol access ioctl paths that call info/get/put callbacks may update the hardware registers. If a system wants to assure the free from such hw access (like the case of PCI rescan feature we're going to implement in future), this situation must be avoided, and we have to sync such in-flight tasks finishing beforehand. For that purpose, this patch introduces a few new things in core code: - A refcount, power_ref, and a wait queue, power_ref_sleep, to the card object - A few new helpers, snd_power_ref(), snd_power_unref(), snd_power_ref_and_wait(), and snd_power_sync_ref() In the code paths that call kctl info/read/write/tlv ops, we check the power state with the newly introduced snd_power_ref_and_wait(). This function also takes the card.power_ref refcount for tracking this in-flight task. Once after the access finishes, snd_power_unref() is called to released the refcount in return. So the driver can sync via snd_power_sync_ref() assuring that all in-flight tasks have been finished. As of this patch, snd_power_sync_ref() is called only at snd_card_disconnect(), but it'll be used in other places in future. Note that atomic_t is used for power_ref intentionally instead of refcount_t. It's because of the design of refcount_t type; refcount_t cannot be zero-based, and it cannot do dec_and_test() call for multiple times, hence it's not suitable for our purpose. Also, this patch changes snd_power_wait() to accept only SNDRV_CTL_POWER_D0, which is the only value that makes sense. In later patch, the snd_power_wait() calls will be cleaned up. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20210523090920.15345-3-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-23 17:09:16 +08:00
init_waitqueue_head(&card->power_ref_sleep);
atomic_set(&card->power_ref, 0);
#endif
ALSA: add snd_card_disconnect_sync() In case of user unbind ALSA driver during playing back / capturing, each driver needs to stop and remove it correctly. One note here is that we can't cancel from remove function in such case, because unbind operation doesn't check return value from remove function. So, we *must* stop and remove in this case. For this purpose, we need to sync (= wait) until the all top-level operations are canceled at remove function. For example, snd_card_free() processes the disconnection procedure at first, then waits for the completion. That's how the hot-unplug works safely. It's implemented, at least, in the top-level driver removal. Now for the lower level driver, we need a similar strategy. Notify to the toplevel for hot-unplug (disconnect in ALSA), and sync with the stop operation, then continue the rest of its own remove procedure. This patch adds snd_card_disconnect_sync(), and driver can use it from remove function. Note: the "lower level" driver here refers to a middle layer driver (e.g. ASoC components) that can be unbound freely during operation. Most of legacy ALSA helper drivers don't have such a problem because they can't be unbound. Note#2: snd_card_disconnect_sync() merely calls snd_card_disconnect() and syncs with closing all pending files. It takes only the files opened by user-space into account, and doesn't care about object refcounts. (The latter is handled by snd_card_free() completion call, BTW.) Also, the function doesn't free resources by itself. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-10-11 14:36:13 +08:00
init_waitqueue_head(&card->remove_sleep);
card->sync_irq = -1;
device_initialize(&card->card_dev);
card->card_dev.parent = parent;
card->card_dev.class = sound_class;
card->card_dev.release = release_card_device;
card->card_dev.groups = card->dev_groups;
card->dev_groups[0] = &card_dev_attr_group;
err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
if (err < 0)
goto __error;
snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
dev_driver_string(card->dev), dev_name(&card->card_dev));
/* the control interface cannot be accessed from the user space until */
/* snd_cards_bitmask and snd_cards are set with snd_card_register */
err = snd_ctl_create(card);
if (err < 0) {
dev_err(parent, "unable to register control minors\n");
goto __error;
}
err = snd_info_card_create(card);
if (err < 0) {
dev_err(parent, "unable to create card info\n");
goto __error_ctl;
}
ALSA: jack: implement software jack injection via debugfs This change adds audio jack injection feature through debugfs, with this feature, we could validate alsa userspace changes by injecting plugin or plugout events to the non-phantom audio jacks. With this change, the sound core will build the folders $debugfs_mount_dir/sound/cardN if SND_DEBUG and DEBUG_FS are enabled. And if users also enable the SND_JACK_INJECTION_DEBUG, the jack injection nodes will be built in the folder cardN like below: $tree $debugfs_mount_dir/sound $debugfs_mount_dir/sound ├── card0 │   ├── HDMI_DP_pcm_10_Jack │   │   ├── jackin_inject │   │   ├── kctl_id │   │   ├── mask_bits │   │   ├── status │   │   ├── sw_inject_enable │   │   └── type ... │   └── HDMI_DP_pcm_9_Jack │   ├── jackin_inject │   ├── kctl_id │   ├── mask_bits │   ├── status │   ├── sw_inject_enable │   └── type └── card1 ├── HDMI_DP_pcm_5_Jack │   ├── jackin_inject │   ├── kctl_id │   ├── mask_bits │   ├── status │   ├── sw_inject_enable │   └── type ... ├── Headphone_Jack │   ├── jackin_inject │   ├── kctl_id │   ├── mask_bits │   ├── status │   ├── sw_inject_enable │   └── type └── Headset_Mic_Jack ├── jackin_inject ├── kctl_id ├── mask_bits ├── status ├── sw_inject_enable └── type The nodes kctl_id, mask_bits, status and type are read-only, users could check jack or jack_kctl's information through them. The nodes sw_inject_enable and jackin_inject are directly used for injection. The sw_inject_enable is read-write, users could check if software injection is enabled or not on this jack, and users could echo 1 or 0 to enable or disable software injection on this jack. Once the injection is enabled, the jack will not change by hardware events anymore, once the injection is disabled, the jack will restore the last reported hardware events to the jack. The jackin_inject is write-only, if the injection is enabled, users could echo 1 or 0 to this node to inject plugin or plugout events to this jack. For the detailed usage information on these nodes, please refer to Documentation/sound/designs/jack-injection.rst. Reviewed-by: Takashi Iwai <tiwai@suse.de> Reviewed-by: Jaroslav Kysela <perex@perex.cz> Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Signed-off-by: Hui Wang <hui.wang@canonical.com> Link: https://lore.kernel.org/r/20210127085639.74954-2-hui.wang@canonical.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-01-27 16:56:39 +08:00
#ifdef CONFIG_SND_DEBUG
sprintf(name, "card%d", idx);
card->debugfs_root = debugfs_create_dir(name, sound_debugfs_root);
#endif
return 0;
__error_ctl:
snd_device_free_all(card);
__error:
put_device(&card->card_dev);
return err;
}
/**
* snd_card_ref - Get the card object from the index
* @idx: the card index
*
* Returns a card object corresponding to the given index or NULL if not found.
* Release the object via snd_card_unref().
*
* Return: a card object or NULL
*/
struct snd_card *snd_card_ref(int idx)
{
struct snd_card *card;
mutex_lock(&snd_card_mutex);
card = snd_cards[idx];
if (card)
get_device(&card->card_dev);
mutex_unlock(&snd_card_mutex);
return card;
}
EXPORT_SYMBOL_GPL(snd_card_ref);
/* return non-zero if a card is already locked */
int snd_card_locked(int card)
{
int locked;
mutex_lock(&snd_card_mutex);
locked = test_bit(card, snd_cards_lock);
mutex_unlock(&snd_card_mutex);
return locked;
}
static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
{
return -ENODEV;
}
static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
size_t count, loff_t *offset)
{
return -ENODEV;
}
static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
size_t count, loff_t *offset)
{
return -ENODEV;
}
static int snd_disconnect_release(struct inode *inode, struct file *file)
{
struct snd_monitor_file *df = NULL, *_df;
spin_lock(&shutdown_lock);
list_for_each_entry(_df, &shutdown_files, shutdown_list) {
if (_df->file == file) {
df = _df;
list_del_init(&df->shutdown_list);
break;
}
}
spin_unlock(&shutdown_lock);
if (likely(df)) {
if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
df->disconnected_f_op->fasync(-1, file, 0);
return df->disconnected_f_op->release(inode, file);
}
panic("%s(%p, %p) failed!", __func__, inode, file);
}
static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
{
return EPOLLERR | EPOLLNVAL;
}
static long snd_disconnect_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
return -ENODEV;
}
static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
{
return -ENODEV;
}
static int snd_disconnect_fasync(int fd, struct file *file, int on)
{
return -ENODEV;
}
static const struct file_operations snd_shutdown_f_ops =
{
.owner = THIS_MODULE,
.llseek = snd_disconnect_llseek,
.read = snd_disconnect_read,
.write = snd_disconnect_write,
.release = snd_disconnect_release,
.poll = snd_disconnect_poll,
.unlocked_ioctl = snd_disconnect_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = snd_disconnect_ioctl,
#endif
.mmap = snd_disconnect_mmap,
.fasync = snd_disconnect_fasync
};
/**
* snd_card_disconnect - disconnect all APIs from the file-operations (user space)
* @card: soundcard structure
*
* Disconnects all APIs from the file-operations (user space).
*
* Return: Zero, otherwise a negative error code.
*
* Note: The current implementation replaces all active file->f_op with special
* dummy file operations (they do nothing except release).
*/
int snd_card_disconnect(struct snd_card *card)
{
struct snd_monitor_file *mfile;
if (!card)
return -EINVAL;
spin_lock(&card->files_lock);
if (card->shutdown) {
spin_unlock(&card->files_lock);
return 0;
}
card->shutdown = 1;
/* replace file->f_op with special dummy operations */
list_for_each_entry(mfile, &card->files_list, list) {
/* it's critical part, use endless loop */
/* we have no room to fail */
mfile->disconnected_f_op = mfile->file->f_op;
spin_lock(&shutdown_lock);
list_add(&mfile->shutdown_list, &shutdown_files);
spin_unlock(&shutdown_lock);
mfile->file->f_op = &snd_shutdown_f_ops;
fops_get(mfile->file->f_op);
}
spin_unlock(&card->files_lock);
/* notify all connected devices about disconnection */
/* at this point, they cannot respond to any calls except release() */
#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
if (snd_mixer_oss_notify_callback)
snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
#endif
/* notify all devices that we are disconnected */
snd_device_disconnect_all(card);
if (card->sync_irq > 0)
synchronize_irq(card->sync_irq);
snd_info_card_disconnect(card);
if (card->registered) {
device_del(&card->card_dev);
card->registered = false;
}
/* disable fops (user space) operations for ALSA API */
mutex_lock(&snd_card_mutex);
snd_cards[card->number] = NULL;
clear_bit(card->number, snd_cards_lock);
mutex_unlock(&snd_card_mutex);
#ifdef CONFIG_PM
wake_up(&card->power_sleep);
ALSA: control: Track in-flight control read/write/tlv accesses Although the power state check is performed in various places (e.g. at the entrance of quite a few ioctls), there can be still some pending tasks that already went into the ioctl handler or other ops, and those may access the hardware even after the power state check. For example, kcontrol access ioctl paths that call info/get/put callbacks may update the hardware registers. If a system wants to assure the free from such hw access (like the case of PCI rescan feature we're going to implement in future), this situation must be avoided, and we have to sync such in-flight tasks finishing beforehand. For that purpose, this patch introduces a few new things in core code: - A refcount, power_ref, and a wait queue, power_ref_sleep, to the card object - A few new helpers, snd_power_ref(), snd_power_unref(), snd_power_ref_and_wait(), and snd_power_sync_ref() In the code paths that call kctl info/read/write/tlv ops, we check the power state with the newly introduced snd_power_ref_and_wait(). This function also takes the card.power_ref refcount for tracking this in-flight task. Once after the access finishes, snd_power_unref() is called to released the refcount in return. So the driver can sync via snd_power_sync_ref() assuring that all in-flight tasks have been finished. As of this patch, snd_power_sync_ref() is called only at snd_card_disconnect(), but it'll be used in other places in future. Note that atomic_t is used for power_ref intentionally instead of refcount_t. It's because of the design of refcount_t type; refcount_t cannot be zero-based, and it cannot do dec_and_test() call for multiple times, hence it's not suitable for our purpose. Also, this patch changes snd_power_wait() to accept only SNDRV_CTL_POWER_D0, which is the only value that makes sense. In later patch, the snd_power_wait() calls will be cleaned up. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20210523090920.15345-3-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-23 17:09:16 +08:00
snd_power_sync_ref(card);
#endif
return 0;
}
EXPORT_SYMBOL(snd_card_disconnect);
ALSA: add snd_card_disconnect_sync() In case of user unbind ALSA driver during playing back / capturing, each driver needs to stop and remove it correctly. One note here is that we can't cancel from remove function in such case, because unbind operation doesn't check return value from remove function. So, we *must* stop and remove in this case. For this purpose, we need to sync (= wait) until the all top-level operations are canceled at remove function. For example, snd_card_free() processes the disconnection procedure at first, then waits for the completion. That's how the hot-unplug works safely. It's implemented, at least, in the top-level driver removal. Now for the lower level driver, we need a similar strategy. Notify to the toplevel for hot-unplug (disconnect in ALSA), and sync with the stop operation, then continue the rest of its own remove procedure. This patch adds snd_card_disconnect_sync(), and driver can use it from remove function. Note: the "lower level" driver here refers to a middle layer driver (e.g. ASoC components) that can be unbound freely during operation. Most of legacy ALSA helper drivers don't have such a problem because they can't be unbound. Note#2: snd_card_disconnect_sync() merely calls snd_card_disconnect() and syncs with closing all pending files. It takes only the files opened by user-space into account, and doesn't care about object refcounts. (The latter is handled by snd_card_free() completion call, BTW.) Also, the function doesn't free resources by itself. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-10-11 14:36:13 +08:00
/**
* snd_card_disconnect_sync - disconnect card and wait until files get closed
* @card: card object to disconnect
*
* This calls snd_card_disconnect() for disconnecting all belonging components
* and waits until all pending files get closed.
* It assures that all accesses from user-space finished so that the driver
* can release its resources gracefully.
*/
void snd_card_disconnect_sync(struct snd_card *card)
{
int err;
err = snd_card_disconnect(card);
if (err < 0) {
dev_err(card->dev,
"snd_card_disconnect error (%d), skipping sync\n",
err);
return;
}
spin_lock_irq(&card->files_lock);
wait_event_lock_irq(card->remove_sleep,
list_empty(&card->files_list),
card->files_lock);
spin_unlock_irq(&card->files_lock);
}
EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
static int snd_card_do_free(struct snd_card *card)
{
2021-07-15 15:58:24 +08:00
card->releasing = true;
#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
if (snd_mixer_oss_notify_callback)
snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
#endif
snd_device_free_all(card);
if (card->private_free)
card->private_free(card);
if (snd_info_card_free(card) < 0) {
dev_warn(card->dev, "unable to free card info\n");
/* Not fatal error */
}
#ifdef CONFIG_SND_DEBUG
debugfs_remove(card->debugfs_root);
card->debugfs_root = NULL;
#endif
if (card->release_completion)
complete(card->release_completion);
2021-07-15 15:58:24 +08:00
if (!card->managed)
kfree(card);
return 0;
}
/**
* snd_card_free_when_closed - Disconnect the card, free it later eventually
* @card: soundcard structure
*
* Unlike snd_card_free(), this function doesn't try to release the card
* resource immediately, but tries to disconnect at first. When the card
* is still in use, the function returns before freeing the resources.
* The card resources will be freed when the refcount gets to zero.
*
* Return: zero if successful, or a negative error code
*/
int snd_card_free_when_closed(struct snd_card *card)
{
int ret = snd_card_disconnect(card);
if (ret)
return ret;
put_device(&card->card_dev);
return 0;
}
EXPORT_SYMBOL(snd_card_free_when_closed);
/**
* snd_card_free - frees given soundcard structure
* @card: soundcard structure
*
* This function releases the soundcard structure and the all assigned
* devices automatically. That is, you don't have to release the devices
* by yourself.
*
* This function waits until the all resources are properly released.
*
* Return: Zero. Frees all associated devices and frees the control
* interface associated to given soundcard.
*/
int snd_card_free(struct snd_card *card)
{
DECLARE_COMPLETION_ONSTACK(released);
int ret;
/* The call of snd_card_free() is allowed from various code paths;
* a manual call from the driver and the call via devres_free, and
* we need to avoid double-free. Moreover, the release via devres
* may call snd_card_free() twice due to its nature, we need to have
* the check here at the beginning.
*/
if (card->releasing)
return 0;
card->release_completion = &released;
ret = snd_card_free_when_closed(card);
if (ret)
return ret;
/* wait, until all devices are ready for the free operation */
wait_for_completion(&released);
ALSA: jack: implement software jack injection via debugfs This change adds audio jack injection feature through debugfs, with this feature, we could validate alsa userspace changes by injecting plugin or plugout events to the non-phantom audio jacks. With this change, the sound core will build the folders $debugfs_mount_dir/sound/cardN if SND_DEBUG and DEBUG_FS are enabled. And if users also enable the SND_JACK_INJECTION_DEBUG, the jack injection nodes will be built in the folder cardN like below: $tree $debugfs_mount_dir/sound $debugfs_mount_dir/sound ├── card0 │   ├── HDMI_DP_pcm_10_Jack │   │   ├── jackin_inject │   │   ├── kctl_id │   │   ├── mask_bits │   │   ├── status │   │   ├── sw_inject_enable │   │   └── type ... │   └── HDMI_DP_pcm_9_Jack │   ├── jackin_inject │   ├── kctl_id │   ├── mask_bits │   ├── status │   ├── sw_inject_enable │   └── type └── card1 ├── HDMI_DP_pcm_5_Jack │   ├── jackin_inject │   ├── kctl_id │   ├── mask_bits │   ├── status │   ├── sw_inject_enable │   └── type ... ├── Headphone_Jack │   ├── jackin_inject │   ├── kctl_id │   ├── mask_bits │   ├── status │   ├── sw_inject_enable │   └── type └── Headset_Mic_Jack ├── jackin_inject ├── kctl_id ├── mask_bits ├── status ├── sw_inject_enable └── type The nodes kctl_id, mask_bits, status and type are read-only, users could check jack or jack_kctl's information through them. The nodes sw_inject_enable and jackin_inject are directly used for injection. The sw_inject_enable is read-write, users could check if software injection is enabled or not on this jack, and users could echo 1 or 0 to enable or disable software injection on this jack. Once the injection is enabled, the jack will not change by hardware events anymore, once the injection is disabled, the jack will restore the last reported hardware events to the jack. The jackin_inject is write-only, if the injection is enabled, users could echo 1 or 0 to this node to inject plugin or plugout events to this jack. For the detailed usage information on these nodes, please refer to Documentation/sound/designs/jack-injection.rst. Reviewed-by: Takashi Iwai <tiwai@suse.de> Reviewed-by: Jaroslav Kysela <perex@perex.cz> Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Signed-off-by: Hui Wang <hui.wang@canonical.com> Link: https://lore.kernel.org/r/20210127085639.74954-2-hui.wang@canonical.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-01-27 16:56:39 +08:00
return 0;
}
EXPORT_SYMBOL(snd_card_free);
/* retrieve the last word of shortname or longname */
static const char *retrieve_id_from_card_name(const char *name)
{
const char *spos = name;
while (*name) {
if (isspace(*name) && isalnum(name[1]))
spos = name + 1;
name++;
}
return spos;
}
/* return true if the given id string doesn't conflict any other card ids */
static bool card_id_ok(struct snd_card *card, const char *id)
{
int i;
if (!snd_info_check_reserved_words(id))
return false;
for (i = 0; i < snd_ecards_limit; i++) {
if (snd_cards[i] && snd_cards[i] != card &&
!strcmp(snd_cards[i]->id, id))
return false;
}
return true;
}
/* copy to card->id only with valid letters from nid */
static void copy_valid_id_string(struct snd_card *card, const char *src,
const char *nid)
{
char *id = card->id;
while (*nid && !isalnum(*nid))
nid++;
if (isdigit(*nid))
*id++ = isalpha(*src) ? *src : 'D';
while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
if (isalnum(*nid))
*id++ = *nid;
nid++;
}
*id = 0;
}
/* Set card->id from the given string
* If the string conflicts with other ids, add a suffix to make it unique.
*/
static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
const char *nid)
{
int len, loops;
bool is_default = false;
char *id;
copy_valid_id_string(card, src, nid);
id = card->id;
again:
/* use "Default" for obviously invalid strings
* ("card" conflicts with proc directories)
*/
if (!*id || !strncmp(id, "card", 4)) {
strcpy(id, "Default");
is_default = true;
}
len = strlen(id);
for (loops = 0; loops < SNDRV_CARDS; loops++) {
char *spos;
char sfxstr[5]; /* "_012" */
int sfxlen;
if (card_id_ok(card, id))
return; /* OK */
/* Add _XYZ suffix */
sprintf(sfxstr, "_%X", loops + 1);
sfxlen = strlen(sfxstr);
if (len + sfxlen >= sizeof(card->id))
spos = id + sizeof(card->id) - sfxlen - 1;
else
spos = id + len;
strcpy(spos, sfxstr);
}
/* fallback to the default id */
if (!is_default) {
*id = 0;
goto again;
}
/* last resort... */
dev_err(card->dev, "unable to set card id (%s)\n", id);
if (card->proc_root->name)
strscpy(card->id, card->proc_root->name, sizeof(card->id));
}
/**
* snd_card_set_id - set card identification name
* @card: soundcard structure
* @nid: new identification string
*
* This function sets the card identification and checks for name
* collisions.
*/
void snd_card_set_id(struct snd_card *card, const char *nid)
{
/* check if user specified own card->id */
if (card->id[0] != '\0')
return;
mutex_lock(&snd_card_mutex);
snd_card_set_id_no_lock(card, nid, nid);
mutex_unlock(&snd_card_mutex);
}
EXPORT_SYMBOL(snd_card_set_id);
static ssize_t id_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct snd_card *card = container_of(dev, struct snd_card, card_dev);
return sysfs_emit(buf, "%s\n", card->id);
}
static ssize_t id_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct snd_card *card = container_of(dev, struct snd_card, card_dev);
char buf1[sizeof(card->id)];
size_t copy = count > sizeof(card->id) - 1 ?
sizeof(card->id) - 1 : count;
size_t idx;
int c;
for (idx = 0; idx < copy; idx++) {
c = buf[idx];
if (!isalnum(c) && c != '_' && c != '-')
return -EINVAL;
}
memcpy(buf1, buf, copy);
buf1[copy] = '\0';
mutex_lock(&snd_card_mutex);
if (!card_id_ok(NULL, buf1)) {
mutex_unlock(&snd_card_mutex);
return -EEXIST;
}
strcpy(card->id, buf1);
snd_info_card_id_change(card);
mutex_unlock(&snd_card_mutex);
return count;
}
static DEVICE_ATTR_RW(id);
static ssize_t number_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct snd_card *card = container_of(dev, struct snd_card, card_dev);
return sysfs_emit(buf, "%i\n", card->number);
}
static DEVICE_ATTR_RO(number);
static struct attribute *card_dev_attrs[] = {
&dev_attr_id.attr,
&dev_attr_number.attr,
NULL
};
static const struct attribute_group card_dev_attr_group = {
.attrs = card_dev_attrs,
};
/**
* snd_card_add_dev_attr - Append a new sysfs attribute group to card
* @card: card instance
* @group: attribute group to append
*
* Return: zero if successful, or a negative error code
*/
int snd_card_add_dev_attr(struct snd_card *card,
const struct attribute_group *group)
{
int i;
/* loop for (arraysize-1) here to keep NULL at the last entry */
for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
if (!card->dev_groups[i]) {
card->dev_groups[i] = group;
return 0;
}
}
dev_err(card->dev, "Too many groups assigned\n");
return -ENOSPC;
}
EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
2021-07-15 15:58:24 +08:00
static void trigger_card_free(void *data)
{
snd_card_free(data);
2021-07-15 15:58:24 +08:00
}
/**
* snd_card_register - register the soundcard
* @card: soundcard structure
*
* This function registers all the devices assigned to the soundcard.
* Until calling this, the ALSA control interface is blocked from the
* external accesses. Thus, you should call this function at the end
* of the initialization of the card.
*
* Return: Zero otherwise a negative error code if the registration failed.
*/
int snd_card_register(struct snd_card *card)
{
int err;
if (snd_BUG_ON(!card))
return -EINVAL;
if (!card->registered) {
err = device_add(&card->card_dev);
if (err < 0)
return err;
card->registered = true;
2021-07-15 15:58:24 +08:00
} else {
if (card->managed)
devm_remove_action(card->dev, trigger_card_free, card);
}
if (card->managed) {
err = devm_add_action(card->dev, trigger_card_free, card);
if (err < 0)
return err;
}
err = snd_device_register_all(card);
if (err < 0)
return err;
mutex_lock(&snd_card_mutex);
if (snd_cards[card->number]) {
/* already registered */
mutex_unlock(&snd_card_mutex);
return snd_info_card_register(card); /* register pending info */
}
if (*card->id) {
/* make a unique id name from the given string */
char tmpid[sizeof(card->id)];
memcpy(tmpid, card->id, sizeof(card->id));
snd_card_set_id_no_lock(card, tmpid, tmpid);
} else {
/* create an id from either shortname or longname */
const char *src;
src = *card->shortname ? card->shortname : card->longname;
snd_card_set_id_no_lock(card, src,
retrieve_id_from_card_name(src));
}
snd_cards[card->number] = card;
mutex_unlock(&snd_card_mutex);
err = snd_info_card_register(card);
if (err < 0)
return err;
#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
if (snd_mixer_oss_notify_callback)
snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
#endif
return 0;
}
EXPORT_SYMBOL(snd_card_register);
#ifdef CONFIG_SND_PROC_FS
static void snd_card_info_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
int idx, count;
struct snd_card *card;
for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
mutex_lock(&snd_card_mutex);
card = snd_cards[idx];
if (card) {
count++;
snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
idx,
card->id,
card->driver,
card->shortname);
snd_iprintf(buffer, " %s\n",
card->longname);
}
mutex_unlock(&snd_card_mutex);
}
if (!count)
snd_iprintf(buffer, "--- no soundcards ---\n");
}
#ifdef CONFIG_SND_OSSEMUL
void snd_card_info_read_oss(struct snd_info_buffer *buffer)
{
int idx, count;
struct snd_card *card;
for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
mutex_lock(&snd_card_mutex);
card = snd_cards[idx];
if (card) {
count++;
snd_iprintf(buffer, "%s\n", card->longname);
}
mutex_unlock(&snd_card_mutex);
}
if (!count) {
snd_iprintf(buffer, "--- no soundcards ---\n");
}
}
#endif
#ifdef MODULE
static void snd_card_module_info_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
int idx;
struct snd_card *card;
for (idx = 0; idx < SNDRV_CARDS; idx++) {
mutex_lock(&snd_card_mutex);
card = snd_cards[idx];
if (card)
snd_iprintf(buffer, "%2i %s\n",
idx, card->module->name);
mutex_unlock(&snd_card_mutex);
}
}
#endif
int __init snd_card_info_init(void)
{
struct snd_info_entry *entry;
entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
if (! entry)
return -ENOMEM;
entry->c.text.read = snd_card_info_read;
if (snd_info_register(entry) < 0)
return -ENOMEM; /* freed in error path */
#ifdef MODULE
entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
if (!entry)
return -ENOMEM;
entry->c.text.read = snd_card_module_info_read;
if (snd_info_register(entry) < 0)
return -ENOMEM; /* freed in error path */
#endif
return 0;
}
#endif /* CONFIG_SND_PROC_FS */
/**
* snd_component_add - add a component string
* @card: soundcard structure
* @component: the component id string
*
* This function adds the component id string to the supported list.
* The component can be referred from the alsa-lib.
*
* Return: Zero otherwise a negative error code.
*/
int snd_component_add(struct snd_card *card, const char *component)
{
char *ptr;
int len = strlen(component);
ptr = strstr(card->components, component);
if (ptr != NULL) {
if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
return 1;
}
if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
snd_BUG();
return -ENOMEM;
}
if (card->components[0] != '\0')
strcat(card->components, " ");
strcat(card->components, component);
return 0;
}
EXPORT_SYMBOL(snd_component_add);
/**
* snd_card_file_add - add the file to the file list of the card
* @card: soundcard structure
* @file: file pointer
*
* This function adds the file to the file linked-list of the card.
* This linked-list is used to keep tracking the connection state,
* and to avoid the release of busy resources by hotplug.
*
* Return: zero or a negative error code.
*/
int snd_card_file_add(struct snd_card *card, struct file *file)
{
struct snd_monitor_file *mfile;
mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
if (mfile == NULL)
return -ENOMEM;
mfile->file = file;
mfile->disconnected_f_op = NULL;
INIT_LIST_HEAD(&mfile->shutdown_list);
spin_lock(&card->files_lock);
if (card->shutdown) {
spin_unlock(&card->files_lock);
kfree(mfile);
return -ENODEV;
}
list_add(&mfile->list, &card->files_list);
get_device(&card->card_dev);
spin_unlock(&card->files_lock);
return 0;
}
EXPORT_SYMBOL(snd_card_file_add);
/**
* snd_card_file_remove - remove the file from the file list
* @card: soundcard structure
* @file: file pointer
*
* This function removes the file formerly added to the card via
* snd_card_file_add() function.
* If all files are removed and snd_card_free_when_closed() was
* called beforehand, it processes the pending release of
* resources.
*
* Return: Zero or a negative error code.
*/
int snd_card_file_remove(struct snd_card *card, struct file *file)
{
struct snd_monitor_file *mfile, *found = NULL;
spin_lock(&card->files_lock);
list_for_each_entry(mfile, &card->files_list, list) {
if (mfile->file == file) {
list_del(&mfile->list);
spin_lock(&shutdown_lock);
list_del(&mfile->shutdown_list);
spin_unlock(&shutdown_lock);
if (mfile->disconnected_f_op)
fops_put(mfile->disconnected_f_op);
found = mfile;
break;
}
}
ALSA: add snd_card_disconnect_sync() In case of user unbind ALSA driver during playing back / capturing, each driver needs to stop and remove it correctly. One note here is that we can't cancel from remove function in such case, because unbind operation doesn't check return value from remove function. So, we *must* stop and remove in this case. For this purpose, we need to sync (= wait) until the all top-level operations are canceled at remove function. For example, snd_card_free() processes the disconnection procedure at first, then waits for the completion. That's how the hot-unplug works safely. It's implemented, at least, in the top-level driver removal. Now for the lower level driver, we need a similar strategy. Notify to the toplevel for hot-unplug (disconnect in ALSA), and sync with the stop operation, then continue the rest of its own remove procedure. This patch adds snd_card_disconnect_sync(), and driver can use it from remove function. Note: the "lower level" driver here refers to a middle layer driver (e.g. ASoC components) that can be unbound freely during operation. Most of legacy ALSA helper drivers don't have such a problem because they can't be unbound. Note#2: snd_card_disconnect_sync() merely calls snd_card_disconnect() and syncs with closing all pending files. It takes only the files opened by user-space into account, and doesn't care about object refcounts. (The latter is handled by snd_card_free() completion call, BTW.) Also, the function doesn't free resources by itself. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-10-11 14:36:13 +08:00
if (list_empty(&card->files_list))
wake_up_all(&card->remove_sleep);
spin_unlock(&card->files_lock);
if (!found) {
dev_err(card->dev, "card file remove problem (%p)\n", file);
return -ENOENT;
}
kfree(found);
put_device(&card->card_dev);
return 0;
}
EXPORT_SYMBOL(snd_card_file_remove);
#ifdef CONFIG_PM
/**
ALSA: control: Track in-flight control read/write/tlv accesses Although the power state check is performed in various places (e.g. at the entrance of quite a few ioctls), there can be still some pending tasks that already went into the ioctl handler or other ops, and those may access the hardware even after the power state check. For example, kcontrol access ioctl paths that call info/get/put callbacks may update the hardware registers. If a system wants to assure the free from such hw access (like the case of PCI rescan feature we're going to implement in future), this situation must be avoided, and we have to sync such in-flight tasks finishing beforehand. For that purpose, this patch introduces a few new things in core code: - A refcount, power_ref, and a wait queue, power_ref_sleep, to the card object - A few new helpers, snd_power_ref(), snd_power_unref(), snd_power_ref_and_wait(), and snd_power_sync_ref() In the code paths that call kctl info/read/write/tlv ops, we check the power state with the newly introduced snd_power_ref_and_wait(). This function also takes the card.power_ref refcount for tracking this in-flight task. Once after the access finishes, snd_power_unref() is called to released the refcount in return. So the driver can sync via snd_power_sync_ref() assuring that all in-flight tasks have been finished. As of this patch, snd_power_sync_ref() is called only at snd_card_disconnect(), but it'll be used in other places in future. Note that atomic_t is used for power_ref intentionally instead of refcount_t. It's because of the design of refcount_t type; refcount_t cannot be zero-based, and it cannot do dec_and_test() call for multiple times, hence it's not suitable for our purpose. Also, this patch changes snd_power_wait() to accept only SNDRV_CTL_POWER_D0, which is the only value that makes sense. In later patch, the snd_power_wait() calls will be cleaned up. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20210523090920.15345-3-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-23 17:09:16 +08:00
* snd_power_ref_and_wait - wait until the card gets powered up
* @card: soundcard structure
*
ALSA: control: Track in-flight control read/write/tlv accesses Although the power state check is performed in various places (e.g. at the entrance of quite a few ioctls), there can be still some pending tasks that already went into the ioctl handler or other ops, and those may access the hardware even after the power state check. For example, kcontrol access ioctl paths that call info/get/put callbacks may update the hardware registers. If a system wants to assure the free from such hw access (like the case of PCI rescan feature we're going to implement in future), this situation must be avoided, and we have to sync such in-flight tasks finishing beforehand. For that purpose, this patch introduces a few new things in core code: - A refcount, power_ref, and a wait queue, power_ref_sleep, to the card object - A few new helpers, snd_power_ref(), snd_power_unref(), snd_power_ref_and_wait(), and snd_power_sync_ref() In the code paths that call kctl info/read/write/tlv ops, we check the power state with the newly introduced snd_power_ref_and_wait(). This function also takes the card.power_ref refcount for tracking this in-flight task. Once after the access finishes, snd_power_unref() is called to released the refcount in return. So the driver can sync via snd_power_sync_ref() assuring that all in-flight tasks have been finished. As of this patch, snd_power_sync_ref() is called only at snd_card_disconnect(), but it'll be used in other places in future. Note that atomic_t is used for power_ref intentionally instead of refcount_t. It's because of the design of refcount_t type; refcount_t cannot be zero-based, and it cannot do dec_and_test() call for multiple times, hence it's not suitable for our purpose. Also, this patch changes snd_power_wait() to accept only SNDRV_CTL_POWER_D0, which is the only value that makes sense. In later patch, the snd_power_wait() calls will be cleaned up. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20210523090920.15345-3-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-23 17:09:16 +08:00
* Take the power_ref reference count of the given card, and
* wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
* The refcount is down again while sleeping until power-up, hence this
* function can be used for syncing the floating control ops accesses,
* typically around calling control ops.
*
ALSA: control: Track in-flight control read/write/tlv accesses Although the power state check is performed in various places (e.g. at the entrance of quite a few ioctls), there can be still some pending tasks that already went into the ioctl handler or other ops, and those may access the hardware even after the power state check. For example, kcontrol access ioctl paths that call info/get/put callbacks may update the hardware registers. If a system wants to assure the free from such hw access (like the case of PCI rescan feature we're going to implement in future), this situation must be avoided, and we have to sync such in-flight tasks finishing beforehand. For that purpose, this patch introduces a few new things in core code: - A refcount, power_ref, and a wait queue, power_ref_sleep, to the card object - A few new helpers, snd_power_ref(), snd_power_unref(), snd_power_ref_and_wait(), and snd_power_sync_ref() In the code paths that call kctl info/read/write/tlv ops, we check the power state with the newly introduced snd_power_ref_and_wait(). This function also takes the card.power_ref refcount for tracking this in-flight task. Once after the access finishes, snd_power_unref() is called to released the refcount in return. So the driver can sync via snd_power_sync_ref() assuring that all in-flight tasks have been finished. As of this patch, snd_power_sync_ref() is called only at snd_card_disconnect(), but it'll be used in other places in future. Note that atomic_t is used for power_ref intentionally instead of refcount_t. It's because of the design of refcount_t type; refcount_t cannot be zero-based, and it cannot do dec_and_test() call for multiple times, hence it's not suitable for our purpose. Also, this patch changes snd_power_wait() to accept only SNDRV_CTL_POWER_D0, which is the only value that makes sense. In later patch, the snd_power_wait() calls will be cleaned up. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20210523090920.15345-3-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-23 17:09:16 +08:00
* The caller needs to pull down the refcount via snd_power_unref() later
* no matter whether the error is returned from this function or not.
*
* Return: Zero if successful, or a negative error code.
*/
ALSA: control: Track in-flight control read/write/tlv accesses Although the power state check is performed in various places (e.g. at the entrance of quite a few ioctls), there can be still some pending tasks that already went into the ioctl handler or other ops, and those may access the hardware even after the power state check. For example, kcontrol access ioctl paths that call info/get/put callbacks may update the hardware registers. If a system wants to assure the free from such hw access (like the case of PCI rescan feature we're going to implement in future), this situation must be avoided, and we have to sync such in-flight tasks finishing beforehand. For that purpose, this patch introduces a few new things in core code: - A refcount, power_ref, and a wait queue, power_ref_sleep, to the card object - A few new helpers, snd_power_ref(), snd_power_unref(), snd_power_ref_and_wait(), and snd_power_sync_ref() In the code paths that call kctl info/read/write/tlv ops, we check the power state with the newly introduced snd_power_ref_and_wait(). This function also takes the card.power_ref refcount for tracking this in-flight task. Once after the access finishes, snd_power_unref() is called to released the refcount in return. So the driver can sync via snd_power_sync_ref() assuring that all in-flight tasks have been finished. As of this patch, snd_power_sync_ref() is called only at snd_card_disconnect(), but it'll be used in other places in future. Note that atomic_t is used for power_ref intentionally instead of refcount_t. It's because of the design of refcount_t type; refcount_t cannot be zero-based, and it cannot do dec_and_test() call for multiple times, hence it's not suitable for our purpose. Also, this patch changes snd_power_wait() to accept only SNDRV_CTL_POWER_D0, which is the only value that makes sense. In later patch, the snd_power_wait() calls will be cleaned up. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20210523090920.15345-3-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-23 17:09:16 +08:00
int snd_power_ref_and_wait(struct snd_card *card)
{
ALSA: control: Track in-flight control read/write/tlv accesses Although the power state check is performed in various places (e.g. at the entrance of quite a few ioctls), there can be still some pending tasks that already went into the ioctl handler or other ops, and those may access the hardware even after the power state check. For example, kcontrol access ioctl paths that call info/get/put callbacks may update the hardware registers. If a system wants to assure the free from such hw access (like the case of PCI rescan feature we're going to implement in future), this situation must be avoided, and we have to sync such in-flight tasks finishing beforehand. For that purpose, this patch introduces a few new things in core code: - A refcount, power_ref, and a wait queue, power_ref_sleep, to the card object - A few new helpers, snd_power_ref(), snd_power_unref(), snd_power_ref_and_wait(), and snd_power_sync_ref() In the code paths that call kctl info/read/write/tlv ops, we check the power state with the newly introduced snd_power_ref_and_wait(). This function also takes the card.power_ref refcount for tracking this in-flight task. Once after the access finishes, snd_power_unref() is called to released the refcount in return. So the driver can sync via snd_power_sync_ref() assuring that all in-flight tasks have been finished. As of this patch, snd_power_sync_ref() is called only at snd_card_disconnect(), but it'll be used in other places in future. Note that atomic_t is used for power_ref intentionally instead of refcount_t. It's because of the design of refcount_t type; refcount_t cannot be zero-based, and it cannot do dec_and_test() call for multiple times, hence it's not suitable for our purpose. Also, this patch changes snd_power_wait() to accept only SNDRV_CTL_POWER_D0, which is the only value that makes sense. In later patch, the snd_power_wait() calls will be cleaned up. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20210523090920.15345-3-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-23 17:09:16 +08:00
snd_power_ref(card);
if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
return 0;
wait_event_cmd(card->power_sleep,
card->shutdown ||
snd_power_get_state(card) == SNDRV_CTL_POWER_D0,
snd_power_unref(card), snd_power_ref(card));
return card->shutdown ? -ENODEV : 0;
}
ALSA: control: Track in-flight control read/write/tlv accesses Although the power state check is performed in various places (e.g. at the entrance of quite a few ioctls), there can be still some pending tasks that already went into the ioctl handler or other ops, and those may access the hardware even after the power state check. For example, kcontrol access ioctl paths that call info/get/put callbacks may update the hardware registers. If a system wants to assure the free from such hw access (like the case of PCI rescan feature we're going to implement in future), this situation must be avoided, and we have to sync such in-flight tasks finishing beforehand. For that purpose, this patch introduces a few new things in core code: - A refcount, power_ref, and a wait queue, power_ref_sleep, to the card object - A few new helpers, snd_power_ref(), snd_power_unref(), snd_power_ref_and_wait(), and snd_power_sync_ref() In the code paths that call kctl info/read/write/tlv ops, we check the power state with the newly introduced snd_power_ref_and_wait(). This function also takes the card.power_ref refcount for tracking this in-flight task. Once after the access finishes, snd_power_unref() is called to released the refcount in return. So the driver can sync via snd_power_sync_ref() assuring that all in-flight tasks have been finished. As of this patch, snd_power_sync_ref() is called only at snd_card_disconnect(), but it'll be used in other places in future. Note that atomic_t is used for power_ref intentionally instead of refcount_t. It's because of the design of refcount_t type; refcount_t cannot be zero-based, and it cannot do dec_and_test() call for multiple times, hence it's not suitable for our purpose. Also, this patch changes snd_power_wait() to accept only SNDRV_CTL_POWER_D0, which is the only value that makes sense. In later patch, the snd_power_wait() calls will be cleaned up. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20210523090920.15345-3-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-23 17:09:16 +08:00
EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);
/**
* snd_power_wait - wait until the card gets powered up (old form)
* @card: soundcard structure
*
* Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
*
* Return: Zero if successful, or a negative error code.
*/
int snd_power_wait(struct snd_card *card)
ALSA: control: Track in-flight control read/write/tlv accesses Although the power state check is performed in various places (e.g. at the entrance of quite a few ioctls), there can be still some pending tasks that already went into the ioctl handler or other ops, and those may access the hardware even after the power state check. For example, kcontrol access ioctl paths that call info/get/put callbacks may update the hardware registers. If a system wants to assure the free from such hw access (like the case of PCI rescan feature we're going to implement in future), this situation must be avoided, and we have to sync such in-flight tasks finishing beforehand. For that purpose, this patch introduces a few new things in core code: - A refcount, power_ref, and a wait queue, power_ref_sleep, to the card object - A few new helpers, snd_power_ref(), snd_power_unref(), snd_power_ref_and_wait(), and snd_power_sync_ref() In the code paths that call kctl info/read/write/tlv ops, we check the power state with the newly introduced snd_power_ref_and_wait(). This function also takes the card.power_ref refcount for tracking this in-flight task. Once after the access finishes, snd_power_unref() is called to released the refcount in return. So the driver can sync via snd_power_sync_ref() assuring that all in-flight tasks have been finished. As of this patch, snd_power_sync_ref() is called only at snd_card_disconnect(), but it'll be used in other places in future. Note that atomic_t is used for power_ref intentionally instead of refcount_t. It's because of the design of refcount_t type; refcount_t cannot be zero-based, and it cannot do dec_and_test() call for multiple times, hence it's not suitable for our purpose. Also, this patch changes snd_power_wait() to accept only SNDRV_CTL_POWER_D0, which is the only value that makes sense. In later patch, the snd_power_wait() calls will be cleaned up. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20210523090920.15345-3-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-23 17:09:16 +08:00
{
int ret;
ret = snd_power_ref_and_wait(card);
snd_power_unref(card);
return ret;
}
EXPORT_SYMBOL(snd_power_wait);
#endif /* CONFIG_PM */