This driver is currently specifying a video_device lock,
which means it is protecting all the ioctls (including
queue ioctls) with a single mutex.
It's therefore straightforward to implement wait_prepare
and wait_finish, by explicitly setting the vb2_queue lock.
Having these callbacks releases the queue lock while blocking,
which improves latency by allowing for example streamoff
or qbuf operations while waiting in dqbuf.
Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
---
drivers/media/platform/m2m-deinterlace.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/media/platform/m2m-deinterlace.c b/drivers/media/platform/m2m-deinterlace.c
index 1e4195144f39..94dd8ec0f265 100644
--- a/drivers/media/platform/m2m-deinterlace.c
+++ b/drivers/media/platform/m2m-deinterlace.c
@@ -856,6 +856,8 @@ static const struct vb2_ops deinterlace_qops = {
.queue_setup = deinterlace_queue_setup,
.buf_prepare = deinterlace_buf_prepare,
.buf_queue = deinterlace_buf_queue,
+ .wait_prepare = vb2_ops_wait_prepare,
+ .wait_finish = vb2_ops_wait_finish,
};
static int queue_init(void *priv, struct vb2_queue *src_vq,
@@ -872,6 +874,7 @@ static int queue_init(void *priv, struct vb2_queue *src_vq,
src_vq->mem_ops = &vb2_dma_contig_memops;
src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
src_vq->dev = ctx->dev->v4l2_dev.dev;
+ src_vq->lock = &ctx->dev->dev_mutex;
q_data[V4L2_M2M_SRC].fmt = &formats[0];
q_data[V4L2_M2M_SRC].width = 640;
q_data[V4L2_M2M_SRC].height = 480;
@@ -890,6 +893,7 @@ static int queue_init(void *priv, struct vb2_queue *src_vq,
dst_vq->mem_ops = &vb2_dma_contig_memops;
dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
dst_vq->dev = ctx->dev->v4l2_dev.dev;
+ dst_vq->lock = &ctx->dev->dev_mutex;
q_data[V4L2_M2M_DST].fmt = &formats[0];
q_data[V4L2_M2M_DST].width = 640;
q_data[V4L2_M2M_DST].height = 480;
--
2.16.3
