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| author | Hans Verkuil <hans.verkuil@cisco.com> | 2014-09-20 16:16:35 -0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-10-09 12:21:27 -0700 |
| commit | cbb87efb98dfabed6dd73b040f25badeaf319960 (patch) | |
| tree | 560d9c5105679d9604994ab10d15edd0281a2def /drivers | |
| parent | 5f50c44d8a63ee6c4801cdcb372b8048ac77efcf (diff) | |
| download | linux-stable-cbb87efb98dfabed6dd73b040f25badeaf319960.tar.gz linux-stable-cbb87efb98dfabed6dd73b040f25badeaf319960.tar.bz2 linux-stable-cbb87efb98dfabed6dd73b040f25badeaf319960.zip | |
media: vb2: fix VBI/poll regression
commit 58d75f4b1ce26324b4d809b18f94819843a98731 upstream.
The recent conversion of saa7134 to vb2 unconvered a poll() bug that
broke the teletext applications alevt and mtt. These applications
expect that calling poll() without having called VIDIOC_STREAMON will
cause poll() to return POLLERR. That did not happen in vb2.
This patch fixes that behavior. It also fixes what should happen when
poll() is called when STREAMON is called but no buffers have been
queued. In that case poll() will also return POLLERR, but only for
capture queues since output queues will always return POLLOUT
anyway in that situation.
This brings the vb2 behavior in line with the old videobuf behavior.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/media/v4l2-core/videobuf2-core.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index a127925c9d61..06faea4d60ee 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -745,6 +745,7 @@ static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) * to the userspace. */ req->count = allocated_buffers; + q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type); return 0; } @@ -793,6 +794,7 @@ static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create memset(q->plane_sizes, 0, sizeof(q->plane_sizes)); memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx)); q->memory = create->memory; + q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type); } num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers); @@ -1447,6 +1449,7 @@ static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b) * dequeued in dqbuf. */ list_add_tail(&vb->queued_entry, &q->queued_list); + q->waiting_for_buffers = false; vb->state = VB2_BUF_STATE_QUEUED; /* @@ -1841,6 +1844,7 @@ static int vb2_internal_streamoff(struct vb2_queue *q, enum v4l2_buf_type type) * and videobuf, effectively returning control over them to userspace. */ __vb2_queue_cancel(q); + q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type); dprintk(3, "Streamoff successful\n"); return 0; @@ -2150,9 +2154,16 @@ unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait) } /* - * There is nothing to wait for if no buffers have already been queued. + * There is nothing to wait for if the queue isn't streaming. */ - if (list_empty(&q->queued_list)) + if (!vb2_is_streaming(q)) + return res | POLLERR; + /* + * For compatibility with vb1: if QBUF hasn't been called yet, then + * return POLLERR as well. This only affects capture queues, output + * queues will always initialize waiting_for_buffers to false. + */ + if (q->waiting_for_buffers) return res | POLLERR; if (list_empty(&q->done_list)) |