Commit d9a98588 authored by Tiffany Lin's avatar Tiffany Lin Committed by Mauro Carvalho Chehab

[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: 199d101e ("v4l: vb2-dma-contig: add prepare/finish to dma-contig allocator")

Cc: # for v3.8 and up
Signed-off-by: default avatarTiffany Lin <>
Signed-off-by: default avatarSakari Ailus <>
Signed-off-by: default avatarMauro Carvalho Chehab <>
parent f06d8902
......@@ -100,7 +100,8 @@ static void vb2_dc_prepare(void *buf_priv)
if (!sgt || buf->db_attach)
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,
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)
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);
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