V4L/DVB (7488): videobuf: Simplify videobuf_waiton logic and possibly avoid missed wakeup
Possible missed wakeup- use kernel helpers for wait queues
http://www.mail-archive.com/linux-usb-devel@lists.sourceforge.net/msg27983.html
Signed-off-by: Brandon Philips <bphilips@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c
index e4a864e..1ba3aaa 100644
--- a/drivers/media/video/videobuf-core.c
+++ b/drivers/media/video/videobuf-core.c
@@ -64,32 +64,25 @@
return vb;
}
+#define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\
+ vb->state != VIDEOBUF_QUEUED)
int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
{
- int retval = 0;
- DECLARE_WAITQUEUE(wait, current);
-
MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
- add_wait_queue(&vb->done, &wait);
- while (vb->state == VIDEOBUF_ACTIVE || vb->state == VIDEOBUF_QUEUED) {
- if (non_blocking) {
- retval = -EAGAIN;
- break;
- }
- set_current_state(intr ? TASK_INTERRUPTIBLE
- : TASK_UNINTERRUPTIBLE);
- if (vb->state == VIDEOBUF_ACTIVE ||
- vb->state == VIDEOBUF_QUEUED)
- schedule();
- set_current_state(TASK_RUNNING);
- if (intr && signal_pending(current)) {
- dprintk(1, "buffer waiton: -EINTR\n");
- retval = -EINTR;
- break;
- }
+
+ if (non_blocking) {
+ if (WAITON_CONDITION)
+ return 0;
+ else
+ return -EAGAIN;
}
- remove_wait_queue(&vb->done, &wait);
- return retval;
+
+ if (intr)
+ return wait_event_interruptible(vb->done, WAITON_CONDITION);
+ else
+ wait_event(vb->done, WAITON_CONDITION);
+
+ return 0;
}
int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,