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 1434e23..7a489aa 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -2317,6 +2317,7 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read) goto err_reqbufs; fileio->bufs[i].queued = 1; } + fileio->index = q->num_buffers; } /* @@ -2392,15 +2393,11 @@ 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. */ @@ -2413,12 +2410,18 @@ 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]; } /* @@ -2481,13 +2484,10 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html