[v2] media: s5p-mfc: Corrected NV12M/NV21M plane-sizes

[Patch v2] media: s5p-mfc: Corrected NV12M/NV21M plane-sizes

Posted by Aakarsh Jain 11 months, 2 weeks ago

There is a possibility of getting page fault if the overall
buffer size is not aligned to 256bytes. Since MFC does read
operation only and it won't corrupt the data values even if
it reads the extra bytes.
Corrected luma and chroma plane sizes for V4L2_PIX_FMT_NV12M
and V4L2_PIX_FMT_NV21M pixel format.

Suggested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Aakarsh Jain <aakarsh.jain@samsung.com>
---
changelog:
v1->v2
Patch link: https://patchwork.kernel.org/project/linux-media/patch/20240806115714.29828-1-aakarsh.jain@samsung.com/
Removed duplicate code and aligned luma and chroma size
to multiple of 256bytes as suggested by Hans.
 drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c
index 73f7af674c01..0c636090d723 100644
--- a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c
+++ b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c
@@ -549,8 +549,9 @@ static void s5p_mfc_enc_calc_src_size_v6(struct s5p_mfc_ctx *ctx)
 		case V4L2_PIX_FMT_NV21M:
 			ctx->stride[0] = ALIGN(ctx->img_width, S5P_FIMV_NV12M_HALIGN_V6);
 			ctx->stride[1] = ALIGN(ctx->img_width, S5P_FIMV_NV12M_HALIGN_V6);
-			ctx->luma_size = ctx->stride[0] * ALIGN(ctx->img_height, 16);
-			ctx->chroma_size =  ctx->stride[0] * ALIGN(ctx->img_height / 2, 16);
+			ctx->luma_size = ALIGN(ctx->stride[0] * ALIGN(ctx->img_height, 16), 256);
+			ctx->chroma_size = ALIGN(ctx->stride[0] * ALIGN(ctx->img_height / 2, 16),
+					256);
 			break;
 		case V4L2_PIX_FMT_YUV420M:
 		case V4L2_PIX_FMT_YVU420M:
-- 
2.17.1

Re: [Patch v2] media: s5p-mfc: Corrected NV12M/NV21M plane-sizes

Posted by Marek Szyprowski 11 months, 2 weeks ago

On 26.02.2025 11:22, Aakarsh Jain wrote:
> There is a possibility of getting page fault if the overall
> buffer size is not aligned to 256bytes. Since MFC does read
> operation only and it won't corrupt the data values even if
> it reads the extra bytes.
> Corrected luma and chroma plane sizes for V4L2_PIX_FMT_NV12M
> and V4L2_PIX_FMT_NV21M pixel format.
>
> Suggested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> Signed-off-by: Aakarsh Jain <aakarsh.jain@samsung.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
> changelog:
> v1->v2
> Patch link: https://patchwork.kernel.org/project/linux-media/patch/20240806115714.29828-1-aakarsh.jain@samsung.com/
> Removed duplicate code and aligned luma and chroma size
> to multiple of 256bytes as suggested by Hans.
>   drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c
> index 73f7af674c01..0c636090d723 100644
> --- a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c
> +++ b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c
> @@ -549,8 +549,9 @@ static void s5p_mfc_enc_calc_src_size_v6(struct s5p_mfc_ctx *ctx)
>   		case V4L2_PIX_FMT_NV21M:
>   			ctx->stride[0] = ALIGN(ctx->img_width, S5P_FIMV_NV12M_HALIGN_V6);
>   			ctx->stride[1] = ALIGN(ctx->img_width, S5P_FIMV_NV12M_HALIGN_V6);
> -			ctx->luma_size = ctx->stride[0] * ALIGN(ctx->img_height, 16);
> -			ctx->chroma_size =  ctx->stride[0] * ALIGN(ctx->img_height / 2, 16);
> +			ctx->luma_size = ALIGN(ctx->stride[0] * ALIGN(ctx->img_height, 16), 256);
> +			ctx->chroma_size = ALIGN(ctx->stride[0] * ALIGN(ctx->img_height / 2, 16),
> +					256);
>   			break;
>   		case V4L2_PIX_FMT_YUV420M:
>   		case V4L2_PIX_FMT_YVU420M:

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland

Re: [Patch v2] media: s5p-mfc: Corrected NV12M/NV21M plane-sizes

Posted by Nicolas Dufresne 11 months, 2 weeks ago

Hi,

Le mercredi 26 février 2025 à 15:52 +0530, Aakarsh Jain a écrit :
> There is a possibility of getting page fault if the overall
> buffer size is not aligned to 256bytes. Since MFC does read
> operation only and it won't corrupt the data values even if
> it reads the extra bytes.
> Corrected luma and chroma plane sizes for V4L2_PIX_FMT_NV12M
> and V4L2_PIX_FMT_NV21M pixel format.
> 
> Suggested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> Signed-off-by: Aakarsh Jain <aakarsh.jain@samsung.com>
> ---
> changelog:
> v1->v2
> Patch link: https://patchwork.kernel.org/project/linux-media/patch/20240806115714.29828-1-aakarsh.jain@samsung.com/
> Removed duplicate code and aligned luma and chroma size
> to multiple of 256bytes as suggested by Hans.
>  drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c
> index 73f7af674c01..0c636090d723 100644
> --- a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c
> +++ b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c
> @@ -549,8 +549,9 @@ static void s5p_mfc_enc_calc_src_size_v6(struct s5p_mfc_ctx *ctx)
>  		case V4L2_PIX_FMT_NV21M:
>  			ctx->stride[0] = ALIGN(ctx->img_width, S5P_FIMV_NV12M_HALIGN_V6);
>  			ctx->stride[1] = ALIGN(ctx->img_width, S5P_FIMV_NV12M_HALIGN_V6);
> -			ctx->luma_size = ctx->stride[0] * ALIGN(ctx->img_height, 16);
> -			ctx->chroma_size =  ctx->stride[0] * ALIGN(ctx->img_height / 2, 16);
> +			ctx->luma_size = ALIGN(ctx->stride[0] * ALIGN(ctx->img_height, 16), 256);
> +			ctx->chroma_size = ALIGN(ctx->stride[0] * ALIGN(ctx->img_height / 2, 16),
> +					256);

An eventual port to v4l2-common helpers instead of open coding this
would be nice, though I see nothing wrong to report with this code, so:

Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>

regards,
Nicolas

>  			break;
>  		case V4L2_PIX_FMT_YUV420M:
>  		case V4L2_PIX_FMT_YVU420M: