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>
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 @@
}
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;
}
- if (intr)
- return wait_event_interruptible(vb->done, WAITON_CONDITION);
- else
- wait_event(vb->done, WAITON_CONDITION);
+ is_ext_locked = q->ext_lock && mutex_is_locked(q->ext_lock);
- return 0;
+ /* 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)
+ ret = wait_event_interruptible(vb->done, is_state_active_or_queued(q, vb));
+ else
+ wait_event(vb->done, is_state_active_or_queued(q, vb));
+ /* Relock */
+ if (is_ext_locked)
+ mutex_lock(q->ext_lock);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(videobuf_waiton);
@@ -671,7 +692,7 @@
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 @@
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 @@
}
/* 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 @@
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;