From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
videobuf2 file I/O emulation assumed that buffers dequeued from the
driver would return in the order they were enqueued in the driver.
Improve the file I/O emulator's book-keeping to remove this assumption.
Also set the buf->size properly if a write() dequeues a buffer and the
VB2_FILEIO_WRITE_IMMEDIATELY flag is set.
Based on an initial patch by Andy Walls.
Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Reviewed-by: Andy Walls <awalls@xxxxxxxxxxxxxxxx>
---
drivers/media/v4l2-core/videobuf2-core.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index a0b931e..af89721 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -2333,6 +2333,7 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
goto err_reqbufs;
fileio->bufs[i].queued = 1;
}
+ fileio->index = q->num_buffers;
}
/*
@@ -2408,15 +2409,11 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
}
fileio = q->fileio;
- index = fileio->index;
- buf = &fileio->bufs[index];
-
/*
* Check if we need to dequeue the buffer.
*/
- if (buf->queued) {
- struct vb2_buffer *vb;
-
+ index = fileio->index;
+ if (index >= q->num_buffers) {
/*
* Call vb2_dqbuf to get buffer back.
*/
@@ -2429,12 +2426,18 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
return ret;
fileio->dq_count += 1;
+ index = fileio->b.index;
+ buf = &fileio->bufs[index];
+
/*
* Get number of bytes filled by the driver
*/
- vb = q->bufs[index];
- buf->size = vb2_get_plane_payload(vb, 0);
+ buf->pos = 0;
buf->queued = 0;
+ buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
+ : vb2_plane_size(q->bufs[index], 0);
+ } else {
+ buf = &fileio->bufs[index];
}
/*
@@ -2497,13 +2500,10 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
*/
buf->pos = 0;
buf->queued = 1;
- buf->size = q->bufs[0]->v4l2_planes[0].length;
+ buf->size = vb2_plane_size(q->bufs[index], 0);
fileio->q_count += 1;
-
- /*
- * Switch to the next buffer
- */
- fileio->index = (index + 1) % q->num_buffers;
+ if (fileio->index < q->num_buffers)
+ fileio->index++;
}
/*
--
1.8.4.3
--
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