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author | Hans Verkuil <hverkuil@xs4all.nl> | 2010-09-26 12:01:26 (GMT) |
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committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2010-10-21 03:06:14 (GMT) |
commit | 0e0809a58869e3e422985f868ad5e0da1fc0ba85 (patch) | |
tree | e4895d60a050e15d6c4b21aa7dbc4090199efdf3 /drivers/media/video/videobuf-core.c | |
parent | 08bff03ed697a583612b62a6ac566bd5bce98012 (diff) | |
download | linux-fsl-qoriq-0e0809a58869e3e422985f868ad5e0da1fc0ba85.tar.xz |
V4L/DVB: videobuf: add queue argument to videobuf_waiton()
videobuf_waiton() must unlock and relock ext_lock if it has to wait.
For that to happen it needs the videobuf_queue pointer.
Don't attempt to unlock/relock q->ext_lock unless it was locked in the
first place.
vb->state has to be protected by a spinlock to be safe.
This patch is based on code from Mauro Carvalho Chehab <mchehab@redhat.com>.
[mchehab@redhat.com: add extra argument to a few missing places]
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/videobuf-core.c')
-rw-r--r-- | drivers/media/video/videobuf-core.c | 47 |
1 files changed, 34 insertions, 13 deletions
diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c index a32ef8e..8979f91 100644 --- a/drivers/media/video/videobuf-core.c +++ b/drivers/media/video/videobuf-core.c @@ -73,25 +73,46 @@ struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q) } EXPORT_SYMBOL_GPL(videobuf_alloc_vb); -#define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\ - vb->state != VIDEOBUF_QUEUED) -int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr) +static int is_state_active_or_queued(struct videobuf_queue *q, struct videobuf_buffer *vb) { + unsigned long flags; + bool rc; + + spin_lock_irqsave(q->irqlock, flags); + rc = vb->state != VIDEOBUF_ACTIVE && vb->state != VIDEOBUF_QUEUED; + spin_unlock_irqrestore(q->irqlock, flags); + return rc; +}; + +int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb, + int non_blocking, int intr) +{ + bool is_ext_locked; + int ret = 0; + MAGIC_CHECK(vb->magic, MAGIC_BUFFER); if (non_blocking) { - if (WAITON_CONDITION) + if (is_state_active_or_queued(q, vb)) return 0; - else - return -EAGAIN; + return -EAGAIN; } + is_ext_locked = q->ext_lock && mutex_is_locked(q->ext_lock); + + /* Release vdev lock to prevent this wait from blocking outside access to + the device. */ + if (is_ext_locked) + mutex_unlock(q->ext_lock); if (intr) - return wait_event_interruptible(vb->done, WAITON_CONDITION); + ret = wait_event_interruptible(vb->done, is_state_active_or_queued(q, vb)); else - wait_event(vb->done, WAITON_CONDITION); + wait_event(vb->done, is_state_active_or_queued(q, vb)); + /* Relock */ + if (is_ext_locked) + mutex_lock(q->ext_lock); - return 0; + return ret; } EXPORT_SYMBOL_GPL(videobuf_waiton); @@ -671,7 +692,7 @@ static int stream_next_buffer(struct videobuf_queue *q, goto done; buf = list_entry(q->stream.next, struct videobuf_buffer, stream); - retval = videobuf_waiton(buf, nonblocking, 1); + retval = videobuf_waiton(q, buf, nonblocking, 1); if (retval < 0) goto done; @@ -799,7 +820,7 @@ static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q, spin_lock_irqsave(q->irqlock, flags); q->ops->buf_queue(q, q->read_buf); spin_unlock_irqrestore(q->irqlock, flags); - retval = videobuf_waiton(q->read_buf, 0, 0); + retval = videobuf_waiton(q, q->read_buf, 0, 0); if (0 == retval) { CALL(q, sync, q, q->read_buf); if (VIDEOBUF_ERROR == q->read_buf->state) @@ -911,7 +932,7 @@ ssize_t videobuf_read_one(struct videobuf_queue *q, } /* wait until capture is done */ - retval = videobuf_waiton(q->read_buf, nonblocking, 1); + retval = videobuf_waiton(q, q->read_buf, nonblocking, 1); if (0 != retval) goto done; @@ -1061,7 +1082,7 @@ ssize_t videobuf_read_stream(struct videobuf_queue *q, list_del(&q->read_buf->stream); q->read_off = 0; } - rc = videobuf_waiton(q->read_buf, nonblocking, 1); + rc = videobuf_waiton(q, q->read_buf, nonblocking, 1); if (rc < 0) { if (0 == retval) retval = rc; |