[RFC][PATCHv2 12/12] videobuf2: don't test db_attach in dma-contig prepare and finish

From: Sergey Senozhatsky
Date: Mon Feb 03 2020 - 21:57:35 EST


We moved cache management decision making to the upper layer and
rely on buffer's need_cache_sync flags and videobuf2 core. If the
upper layer (core) has decided to invoke ->prepare() or ->finish()
then we must sync.

For DMABUF ->need_cache_sync_on_prepare and ->need_cache_sync_on_flush
are always false so videobuf core does not call ->prepare() and
->finish() on such buffers.

Additionally, scratch the DMABUF comment.

Change-Id: I8f6c0b246ccb63f775dcf7881dd5f848c38e7604
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
drivers/media/common/videobuf2/videobuf2-dma-contig.c | 6 ++----
drivers/media/common/videobuf2/videobuf2-dma-sg.c | 8 --------
2 files changed, 2 insertions(+), 12 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index a387260fb321..6ea0961149d7 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -100,8 +100,7 @@ static void vb2_dc_prepare(void *buf_priv)
struct vb2_dc_buf *buf = buf_priv;
struct sg_table *sgt = buf->dma_sgt;

- /* DMABUF exporter will flush the cache for us */
- if (!sgt || buf->db_attach)
+ if (!sgt)
return;

dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
@@ -113,8 +112,7 @@ static void vb2_dc_finish(void *buf_priv)
struct vb2_dc_buf *buf = buf_priv;
struct sg_table *sgt = buf->dma_sgt;

- /* DMABUF exporter will flush the cache for us */
- if (!sgt || buf->db_attach)
+ if (!sgt)
return;

dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
index bfc99a0cb7b9..1fd25eda0bf2 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
@@ -198,10 +198,6 @@ static void vb2_dma_sg_prepare(void *buf_priv)
struct vb2_dma_sg_buf *buf = buf_priv;
struct sg_table *sgt = buf->dma_sgt;

- /* DMABUF exporter will flush the cache for us */
- if (buf->db_attach)
- return;
-
dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
buf->dma_dir);
}
@@ -211,10 +207,6 @@ static void vb2_dma_sg_finish(void *buf_priv)
struct vb2_dma_sg_buf *buf = buf_priv;
struct sg_table *sgt = buf->dma_sgt;

- /* DMABUF exporter will flush the cache for us */
- if (buf->db_attach)
- return;
-
dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
}

--
2.25.0.341.g760bfbb309-goog