V4L/DVB (7281): v4l: Deadlock in videobuf-core for DQBUF waiting on QBUF

Avoid a deadlock where DQBUF is holding the vb_lock while waiting on a QBUF
which also needs the vb_lock.  Reported by Hans Verkuil <hverkuil@xs4all.nl>.

Signed-off-by: Brandon Philips <bphilips@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
This commit is contained in:
Brandon Philips 2008-04-22 14:45:32 -03:00 committed by Mauro Carvalho Chehab
parent 9dc4e48fbe
commit e43d76b40d

View file

@ -605,7 +605,9 @@ int videobuf_dqbuf(struct videobuf_queue *q,
goto done;
}
buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
mutex_unlock(&q->vb_lock);
retval = videobuf_waiton(buf, nonblocking, 1);
mutex_lock(&q->vb_lock);
if (retval < 0) {
dprintk(1, "dqbuf: waiton returned %d\n", retval);
goto done;