diff options
Diffstat (limited to 'drivers/media/common/videobuf2/videobuf2-dma-contig.c')
| -rw-r--r-- | drivers/media/common/videobuf2/videobuf2-dma-contig.c | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c index 7d77e4d30c8a..44cd0e530bbd 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c @@ -267,8 +267,14 @@ static void vb2_dc_dmabuf_ops_detach(struct dma_buf *dbuf, /* release the scatterlist cache */ if (attach->dma_dir != DMA_NONE) - dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - attach->dma_dir); + /* + * Cache sync can be skipped here, as the vb2_dc memory is + * allocated from device coherent memory, which means the + * memory locations do not require any explicit cache + * maintenance prior or after being used by the device. + */ + dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents, + attach->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); sg_free_table(sgt); kfree(attach); db_attach->priv = NULL; @@ -293,14 +299,17 @@ static struct sg_table *vb2_dc_dmabuf_ops_map( /* release any previous cache */ if (attach->dma_dir != DMA_NONE) { - dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - attach->dma_dir); + dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents, + attach->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); attach->dma_dir = DMA_NONE; } - /* mapping to the client with new direction */ - sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - dma_dir); + /* + * mapping to the client with new direction, no cache sync + * required see comment in vb2_dc_dmabuf_ops_detach() + */ + sgt->nents = dma_map_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents, + dma_dir, DMA_ATTR_SKIP_CPU_SYNC); if (!sgt->nents) { pr_err("failed to map scatterlist\n"); mutex_unlock(lock); |