Hi Tomasz,
On 07.09.2020 15:07, Tomasz Figa wrote:
On Fri, Sep 4, 2020 at 3:35 PM Marek Szyprowski m.szyprowski@samsung.com wrote:
Use recently introduced common wrappers operating directly on the struct sg_table objects and scatterlist page iterators to make the code a bit more compact, robust, easier to follow and copy/paste safe.
No functional change, because the code already properly did all the scatterlist related calls.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Reviewed-by: Robin Murphy robin.murphy@arm.com
.../common/videobuf2/videobuf2-dma-contig.c | 34 ++++++++----------- .../media/common/videobuf2/videobuf2-dma-sg.c | 32 +++++++---------- .../common/videobuf2/videobuf2-vmalloc.c | 12 +++---- 3 files changed, 31 insertions(+), 47 deletions(-)
Thanks for the patch! Please see my comments inline.
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c index ec3446cc45b8..1b242d844dde 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c @@ -58,10 +58,10 @@ static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt) unsigned int i; unsigned long size = 0;
for_each_sg(sgt->sgl, s, sgt->nents, i) {
for_each_sgtable_dma_sg(sgt, s, i) { if (sg_dma_address(s) != expected) break;
expected = sg_dma_address(s) + sg_dma_len(s);
expected += sg_dma_len(s); size += sg_dma_len(s); } return size;@@ -103,8 +103,7 @@ static void vb2_dc_prepare(void *buf_priv) if (!sgt) return;
dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,buf->dma_dir);
dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);}
static void vb2_dc_finish(void *buf_priv)
@@ -115,7 +114,7 @@ static void vb2_dc_finish(void *buf_priv) if (!sgt) return;
dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);}
/*********************************************/
@@ -275,8 +274,8 @@ static void vb2_dc_dmabuf_ops_detach(struct dma_buf *dbuf, * 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);
dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,DMA_ATTR_SKIP_CPU_SYNC); sg_free_table(sgt); kfree(attach); db_attach->priv = NULL;@@ -301,8 +300,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
/* release any previous cache */ if (attach->dma_dir != DMA_NONE) {
dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents,attach->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,DMA_ATTR_SKIP_CPU_SYNC); attach->dma_dir = DMA_NONE; }@@ -310,9 +309,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map( * 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) {
if (dma_map_sgtable(db_attach->dev, sgt, dma_dir,DMA_ATTR_SKIP_CPU_SYNC)) { pr_err("failed to map scatterlist\n"); mutex_unlock(lock); return ERR_PTR(-EIO);As opposed to dma_map_sg_attrs(), dma_map_sgtable() now returns an error code on its own. Is it expected to ignore it and return -EIO?
Those errors are more or less propagated to userspace and -EIO has been already widely documented in V4L2 documentation as the error code for the most of the V4L2 ioctls. I don't want to change it. A possible -EINVAL returned from dma_map_sgtable() was just one of the 'generic' error codes, not very descriptive in that case. Probably the main problem here is that dma_map_sg() and friend doesn't return any error codes...
...
Best regards