[PATCH v2 1/3] media: videobuf2: use sgtable-based scatterlist wrappers

[PATCH v2 1/3] media: videobuf2: use sgtable-based scatterlist wrappers

[Marek Szyprowski]

Use common wrappers operating directly on the struct sg_table objects to
fix incorrect use of scatterlists sync calls. dma_sync_sg_for_*()
functions have to be called with the number of elements originally passed
to dma_map_sg_*() function, not the one returned in sgt->nents.

Fixes: d4db5eb57cab ("media: videobuf2: add begin/end cpu_access callbacks to dma-sg")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/media/common/videobuf2/videobuf2-dma-sg.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
index c6ddf2357c58..b3bf2173c14e 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
@@ -469,7 +469,7 @@ vb2_dma_sg_dmabuf_ops_begin_cpu_access(struct dma_buf *dbuf,
 	struct vb2_dma_sg_buf *buf = dbuf->priv;
 	struct sg_table *sgt = buf->dma_sgt;
 
-	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+	dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
 	return 0;
 }
 
@@ -480,7 +480,7 @@ vb2_dma_sg_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf,
 	struct vb2_dma_sg_buf *buf = dbuf->priv;
 	struct sg_table *sgt = buf->dma_sgt;
 
-	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+	dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
 	return 0;
 }
 
-- 
2.34.1

Re: [PATCH v2 1/3] media: videobuf2: use sgtable-based scatterlist wrappers

[Hans Verkuil]

On 07/05/2025 16:42, Marek Szyprowski wrote:
> Use common wrappers operating directly on the struct sg_table objects to
> fix incorrect use of scatterlists sync calls. dma_sync_sg_for_*()
> functions have to be called with the number of elements originally passed
> to dma_map_sg_*() function, not the one returned in sgt->nents.
> 
> Fixes: d4db5eb57cab ("media: videobuf2: add begin/end cpu_access callbacks to dma-sg")

Ah, the Cc to stable should be here, after the Fixes tag :-) E.g.:

Cc: stable@vger.kernel.org

Regards,

	Hans

> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>  drivers/media/common/videobuf2/videobuf2-dma-sg.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> index c6ddf2357c58..b3bf2173c14e 100644
> --- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> +++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> @@ -469,7 +469,7 @@ vb2_dma_sg_dmabuf_ops_begin_cpu_access(struct dma_buf *dbuf,
>  	struct vb2_dma_sg_buf *buf = dbuf->priv;
>  	struct sg_table *sgt = buf->dma_sgt;
>  
> -	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
> +	dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
>  	return 0;
>  }
>  
> @@ -480,7 +480,7 @@ vb2_dma_sg_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf,
>  	struct vb2_dma_sg_buf *buf = dbuf->priv;
>  	struct sg_table *sgt = buf->dma_sgt;
>  
> -	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
> +	dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
>  	return 0;
>  }
>  

[PATCH v2 2/3] udmabuf: use sgtable-based scatterlist wrappers

[Marek Szyprowski]

Use common wrappers operating directly on the struct sg_table objects to
fix incorrect use of scatterlists sync calls. dma_sync_sg_for_*()
functions have to be called with the number of elements originally passed
to dma_map_sg_*() function, not the one returned in sgtable's nents.

Fixes: 1ffe09590121 ("udmabuf: fix dma-buf cpu access")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
---
 drivers/dma-buf/udmabuf.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index 7eee3eb47a8e..c9d0c68d2fcb 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -264,8 +264,7 @@ static int begin_cpu_udmabuf(struct dma_buf *buf,
 			ubuf->sg = NULL;
 		}
 	} else {
-		dma_sync_sg_for_cpu(dev, ubuf->sg->sgl, ubuf->sg->nents,
-				    direction);
+		dma_sync_sgtable_for_cpu(dev, ubuf->sg, direction);
 	}
 
 	return ret;
@@ -280,7 +279,7 @@ static int end_cpu_udmabuf(struct dma_buf *buf,
 	if (!ubuf->sg)
 		return -EINVAL;
 
-	dma_sync_sg_for_device(dev, ubuf->sg->sgl, ubuf->sg->nents, direction);
+	dma_sync_sgtable_for_device(dev, ubuf->sg, direction);
 	return 0;
 }
 
-- 
2.34.1

Re: [PATCH v2 2/3] udmabuf: use sgtable-based scatterlist wrappers

[kernel test robot]

Hi,

Thanks for your patch.

FYI: kernel test robot notices the stable kernel rule is not satisfied.

The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#option-1

Rule: add the tag "Cc: stable@vger.kernel.org" in the sign-off area to have the patch automatically included in the stable tree.
Subject: [PATCH v2 2/3] udmabuf: use sgtable-based scatterlist wrappers
Link: https://lore.kernel.org/stable/20250507144203.2081756-3-m.szyprowski%40samsung.com

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[PATCH v2 3/3] media: omap3isp: use sgtable-based scatterlist wrappers

[Marek Szyprowski]

Use common wrappers operating directly on the struct sg_table objects to
fix incorrect use of scatterlists sync calls. dma_sync_sg_for_*()
functions have to be called with the number of elements originally passed
to dma_map_sg_*() function, not the one returned in sgtable's nents.

Fixes: d33186d0be18 ("[media] omap3isp: ccdc: Use the DMA API for LSC")
Fixes: 0e24e90f2ca7 ("[media] omap3isp: stat: Use the DMA API")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/media/platform/ti/omap3isp/ispccdc.c | 8 ++++----
 drivers/media/platform/ti/omap3isp/ispstat.c | 6 ++----
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/media/platform/ti/omap3isp/ispccdc.c b/drivers/media/platform/ti/omap3isp/ispccdc.c
index dd375c4e180d..7d0c723dcd11 100644
--- a/drivers/media/platform/ti/omap3isp/ispccdc.c
+++ b/drivers/media/platform/ti/omap3isp/ispccdc.c
@@ -446,8 +446,8 @@ static int ccdc_lsc_config(struct isp_ccdc_device *ccdc,
 		if (ret < 0)
 			goto done;
 
-		dma_sync_sg_for_cpu(isp->dev, req->table.sgt.sgl,
-				    req->table.sgt.nents, DMA_TO_DEVICE);
+		dma_sync_sgtable_for_cpu(isp->dev, &req->table.sgt,
+					 DMA_TO_DEVICE);
 
 		if (copy_from_user(req->table.addr, config->lsc,
 				   req->config.size)) {
@@ -455,8 +455,8 @@ static int ccdc_lsc_config(struct isp_ccdc_device *ccdc,
 			goto done;
 		}
 
-		dma_sync_sg_for_device(isp->dev, req->table.sgt.sgl,
-				       req->table.sgt.nents, DMA_TO_DEVICE);
+		dma_sync_sgtable_for_device(isp->dev, &req->table.sgt,
+					    DMA_TO_DEVICE);
 	}
 
 	spin_lock_irqsave(&ccdc->lsc.req_lock, flags);
diff --git a/drivers/media/platform/ti/omap3isp/ispstat.c b/drivers/media/platform/ti/omap3isp/ispstat.c
index 359a846205b0..d3da68408ecb 100644
--- a/drivers/media/platform/ti/omap3isp/ispstat.c
+++ b/drivers/media/platform/ti/omap3isp/ispstat.c
@@ -161,8 +161,7 @@ static void isp_stat_buf_sync_for_device(struct ispstat *stat,
 	if (ISP_STAT_USES_DMAENGINE(stat))
 		return;
 
-	dma_sync_sg_for_device(stat->isp->dev, buf->sgt.sgl,
-			       buf->sgt.nents, DMA_FROM_DEVICE);
+	dma_sync_sgtable_for_device(stat->isp->dev, &buf->sgt, DMA_FROM_DEVICE);
 }
 
 static void isp_stat_buf_sync_for_cpu(struct ispstat *stat,
@@ -171,8 +170,7 @@ static void isp_stat_buf_sync_for_cpu(struct ispstat *stat,
 	if (ISP_STAT_USES_DMAENGINE(stat))
 		return;
 
-	dma_sync_sg_for_cpu(stat->isp->dev, buf->sgt.sgl,
-			    buf->sgt.nents, DMA_FROM_DEVICE);
+	dma_sync_sgtable_for_cpu(stat->isp->dev, &buf->sgt, DMA_FROM_DEVICE);
 }
 
 static void isp_stat_buf_clear(struct ispstat *stat)
-- 
2.34.1