Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1052ef...
Commit: 1052efe0fc69130d9d6a44bc9ceecd229221d9a1
Parent: feb75f07102a85026d41e2c4e4113c34dd035c30
Author: Hans Verkuil <hverkuil@xs4all.nl>
AuthorDate: Sat Jul 26 09:01:24 2008 -0300
Committer: Mauro Carvalho Chehab <mchehab@infradead.org>
CommitDate: Sun Jul 27 11:06:23 2008 -0300
V4L/DVB (8505): saa7134-empress.c: fix deadlock
ts_release() locked a mutex that videobuf_stop() also tried to obtain.
But ts_release() shouldn't hold that mutex at all.
Make empress_users atomic as well to prevent possible race condition.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
---
drivers/media/video/saa7134/saa7134-empress.c | 12 ++++--------
drivers/media/video/saa7134/saa7134.h | 2 +-
2 files changed, 5 insertions(+), 9 deletions(-)
diff --git a/drivers/media/video/saa7134/saa7134-empress.c b/drivers/media/video/saa7134/saa7134-empress.c
index 8b3f951..2ecfbd1 100644
--- a/drivers/media/video/saa7134/saa7134-empress.c
+++ b/drivers/media/video/saa7134/saa7134-empress.c
@@ -89,14 +89,14 @@ static int ts_open(struct inode *inode, struct file *file)
err = -EBUSY;
if (!mutex_trylock(&dev->empress_tsq.vb_lock))
goto done;
- if (dev->empress_users)
+ if (atomic_read(&dev->empress_users))
goto done_up;
/* Unmute audio */
saa_writeb(SAA7134_AUDIO_MUTE_CTRL,
saa_readb(SAA7134_AUDIO_MUTE_CTRL) & ~(1 << 6));
- dev->empress_users++;
+ atomic_inc(&dev->empress_users);
file->private_data = dev;
err = 0;
@@ -110,8 +110,6 @@ static int ts_release(struct inode *inode, struct file *file)
{
struct saa7134_dev *dev = file->private_data;
- mutex_lock(&dev->empress_tsq.vb_lock);
-
videobuf_stop(&dev->empress_tsq);
videobuf_mmap_free(&dev->empress_tsq);
@@ -122,9 +120,7 @@ static int ...
