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[PATCH] ieee1394: dv1394: sem2mutex conversion 

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (not runtime-tested)
Signed-off-by: Ben Collins <bcollins@ubuntu.com>
This commit is contained in:
Stefan Richter 2006-07-03 12:02:32 -04:00 committed by Ben Collins
parent d8831d5554
commit 438bd525e5
2 changed files with 19 additions and 18 deletions
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6
drivers/ieee1394/dv1394-private.h
View File

@ -460,7 +460,7 @@ struct video_card {
int dma_running;
/*
3) the sleeping semaphore 'sem' - this is used from process context only,
3) the sleeping mutex 'mtx' - this is used from process context only,
to serialize various operations on the video_card. Even though only one
open() is allowed, we still need to prevent multiple threads of execution
from entering calls like read, write, ioctl, etc.
@ -468,9 +468,9 @@ struct video_card {
I honestly can't think of a good reason to use dv1394 from several threads
at once, but we need to serialize anyway to prevent oopses =).
NOTE: if you need both spinlock and sem, take sem first to avoid deadlock!
NOTE: if you need both spinlock and mtx, take mtx first to avoid deadlock!
*/
struct semaphore sem;
struct mutex mtx;
/* people waiting for buffer space, please form a line here... */
wait_queue_head_t waitq;

31
drivers/ieee1394/dv1394.c
View File

@ -95,6 +95,7 @@
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/smp_lock.h>
#include <linux/mutex.h>
#include <linux/bitops.h>
#include <asm/byteorder.h>
#include <asm/atomic.h>
@ -247,7 +248,7 @@ static void frame_delete(struct frame *f)
Frame_prepare() must be called OUTSIDE the video->spinlock.
However, frame_prepare() must still be serialized, so
it should be called WITH the video->sem taken.
it should be called WITH the video->mtx taken.
*/
static void frame_prepare(struct video_card *video, unsigned int this_frame)
@ -1271,7 +1272,7 @@ static int dv1394_mmap(struct file *file, struct vm_area_struct *vma)
int retval = -EINVAL;
/* serialize mmap */
down(&video->sem);
mutex_lock(&video->mtx);
if ( ! video_card_initialized(video) ) {
retval = do_dv1394_init_default(video);
@ -1281,7 +1282,7 @@ static int dv1394_mmap(struct file *file, struct vm_area_struct *vma)
retval = dma_region_mmap(&video->dv_buf, file, vma);
out:
up(&video->sem);
mutex_unlock(&video->mtx);
return retval;
}
@ -1337,17 +1338,17 @@ static ssize_t dv1394_write(struct file *file, const char __user *buffer, size_t
/* serialize this to prevent multi-threaded mayhem */
if (file->f_flags & O_NONBLOCK) {
if (down_trylock(&video->sem))
if (!mutex_trylock(&video->mtx))
return -EAGAIN;
} else {
if (down_interruptible(&video->sem))
if (mutex_lock_interruptible(&video->mtx))
return -ERESTARTSYS;
}
if ( !video_card_initialized(video) ) {
ret = do_dv1394_init_default(video);
if (ret) {
up(&video->sem);
mutex_unlock(&video->mtx);
return ret;
}
}
@ -1418,7 +1419,7 @@ static ssize_t dv1394_write(struct file *file, const char __user *buffer, size_t
remove_wait_queue(&video->waitq, &wait);
set_current_state(TASK_RUNNING);
up(&video->sem);
mutex_unlock(&video->mtx);
return ret;
}
@ -1434,17 +1435,17 @@ static ssize_t dv1394_read(struct file *file, char __user *buffer, size_t count
/* serialize this to prevent multi-threaded mayhem */
if (file->f_flags & O_NONBLOCK) {
if (down_trylock(&video->sem))
if (!mutex_trylock(&video->mtx))
return -EAGAIN;
} else {
if (down_interruptible(&video->sem))
if (mutex_lock_interruptible(&video->mtx))
return -ERESTARTSYS;
}
if ( !video_card_initialized(video) ) {
ret = do_dv1394_init_default(video);
if (ret) {
up(&video->sem);
mutex_unlock(&video->mtx);
return ret;
}
video->continuity_counter = -1;
@ -1526,7 +1527,7 @@ static ssize_t dv1394_read(struct file *file, char __user *buffer, size_t count
remove_wait_queue(&video->waitq, &wait);
set_current_state(TASK_RUNNING);
up(&video->sem);
mutex_unlock(&video->mtx);
return ret;
}
@ -1547,12 +1548,12 @@ static long dv1394_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
/* serialize this to prevent multi-threaded mayhem */
if (file->f_flags & O_NONBLOCK) {
if (down_trylock(&video->sem)) {
if (!mutex_trylock(&video->mtx)) {
unlock_kernel();
return -EAGAIN;
}
} else {
if (down_interruptible(&video->sem)) {
if (mutex_lock_interruptible(&video->mtx)) {
unlock_kernel();
return -ERESTARTSYS;
}
@ -1778,7 +1779,7 @@ static long dv1394_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
}
out:
up(&video->sem);
mutex_unlock(&video->mtx);
unlock_kernel();
return ret;
}
@ -2253,7 +2254,7 @@ static int dv1394_init(struct ti_ohci *ohci, enum pal_or_ntsc format, enum modes
clear_bit(0, &video->open);
spin_lock_init(&video->spinlock);
video->dma_running = 0;
init_MUTEX(&video->sem);
mutex_init(&video->mtx);
init_waitqueue_head(&video->waitq);
video->fasync = NULL;