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| author | Hans Verkuil <hverkuil-cisco@xs4all.nl> | 2021-06-30 09:58:23 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2021-07-30 13:01:03 +0200 |
| commit | c592b46907adbeb81243f7eb7a468c36692658b8 (patch) | |
| tree | 3d0a70b8779e798f5d2fa9a236953121d5318cfe /drivers | |
| parent | 76f22c93b209c811bd489950f17f8839adb31901 (diff) | |
| download | linux-c592b46907adbeb81243f7eb7a468c36692658b8.tar.bz2 | |
media: videobuf2-core: dequeue if start_streaming fails
If a vb2_queue sets q->min_buffers_needed then when the number of
queued buffers reaches q->min_buffers_needed, vb2_core_qbuf() will call
the start_streaming() callback. If start_streaming() returns an error,
then that error was just returned by vb2_core_qbuf(), but the buffer
was still queued. However, userspace expects that if VIDIOC_QBUF fails,
the buffer is returned dequeued.
So if start_streaming() fails, then remove the buffer from the queue,
thus avoiding this unwanted side-effect.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Fixes: b3379c6201bb ("[media] vb2: only call start_streaming if sufficient buffers are queued")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/media/common/videobuf2/videobuf2-core.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c index 02281d13505f..508ac295eb06 100644 --- a/drivers/media/common/videobuf2/videobuf2-core.c +++ b/drivers/media/common/videobuf2/videobuf2-core.c @@ -1573,6 +1573,7 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb, struct media_request *req) { struct vb2_buffer *vb; + enum vb2_buffer_state orig_state; int ret; if (q->error) { @@ -1673,6 +1674,7 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb, * Add to the queued buffers list, a buffer will stay on it until * dequeued in dqbuf. */ + orig_state = vb->state; list_add_tail(&vb->queued_entry, &q->queued_list); q->queued_count++; q->waiting_for_buffers = false; @@ -1703,8 +1705,17 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb, if (q->streaming && !q->start_streaming_called && q->queued_count >= q->min_buffers_needed) { ret = vb2_start_streaming(q); - if (ret) + if (ret) { + /* + * Since vb2_core_qbuf will return with an error, + * we should return it to state DEQUEUED since + * the error indicates that the buffer wasn't queued. + */ + list_del(&vb->queued_entry); + q->queued_count--; + vb->state = orig_state; return ret; + } } dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index); |