On Mon, Nov 10, 2014 at 8:49 PM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote: > From: Hans Verkuil <hans.verkuil@xxxxxxxxx> > > By default dma_map_sg syncs the mapped buffer to the device. But > buf_prepare expects a buffer syncs for the cpu and the buffer > will be synced to the device in the prepare memop. > > The reverse is true for dma_unmap_sg, buf_finish and the finish > memop. > > To prevent unnecessary syncs we ask dma_(un)map_sg to skip the > sync. > > Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > --- > drivers/media/v4l2-core/videobuf2-dma-contig.c | 29 +++++++++++++++++----- > drivers/media/v4l2-core/videobuf2-dma-sg.c | 33 +++++++++++++++++++++----- > 2 files changed, 50 insertions(+), 12 deletions(-) > > diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c > index c4305bf..27f5926 100644 > --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c > +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c > @@ -317,8 +317,9 @@ static struct sg_table *vb2_dc_dmabuf_ops_map( > attach->dma_dir = DMA_NONE; > } > > - /* mapping to the client with new direction */ > - ret = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, dma_dir); > + /* Mapping to the client with new direction */ > + ret = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, > + dma_dir); Do we need this chunk? -- Best regards, Pawel Osciak -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
