media: mx_emmaprp: Implement wait_prepare and wait_finish

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@collabora.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Ezequiel Garcia 2018-06-15 15:07:30 -04:00 committed by Mauro Carvalho Chehab
parent 4e55969f23
commit a4273abcd3

View File

@ -733,6 +733,8 @@ static const struct vb2_ops emmaprp_qops = {
.queue_setup = emmaprp_queue_setup,
.buf_prepare = emmaprp_buf_prepare,
.buf_queue = emmaprp_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,
@ -749,6 +751,7 @@ 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;
ret = vb2_queue_init(src_vq);
if (ret)
@ -762,6 +765,7 @@ 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;
return vb2_queue_init(dst_vq);
}