[media] media: vb2 dma-contig: Fully cache synchronise buffers in prepare and finish

In videobuf2 dma-contig memory type the prepare and finish ops, instead of
passing the number of entries in the original scatterlist as the "nents"
parameter to dma_sync_sg_for_device() and dma_sync_sg_for_cpu(), the value
returned by dma_map_sg() was used. Albeit this has been suggested in
comments of some implementations (which have since been corrected), this
is wrong.

Fixes: 199d101efdba ("v4l: vb2-dma-contig: add prepare/finish to dma-contig allocator")

Cc: stable@vger.kernel.org # for v3.8 and up
Signed-off-by: Tiffany Lin <tiffany.lin@mediatek.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index ea33d69bbed964a64dddf7372adc3bf6fff4e74e..c33127284cfeed93ba4bf9993c49c470b8587802 100644 (file)
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -100,7 +100,8 @@ static void vb2_dc_prepare(void *buf_priv)
        if (!sgt || buf->db_attach)
                return;
 
-       dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+       dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
+                              buf->dma_dir);
 }
 
 static void vb2_dc_finish(void *buf_priv)
@@ -112,7 +113,7 @@ static void vb2_dc_finish(void *buf_priv)
        if (!sgt || buf->db_attach)
                return;
 
-       dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+       dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
 }
 
 /*********************************************/