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

Nicolas Dufresne
2024-08-06T14:37:57Z

Hi Jain,

I haven't dig much, but I have a quick question below.

Le mardi 06 août 2024 à 17:27 +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.

Have you re-run v4l2 compliance ? (better be safe then sorry).

>
> Signed-off-by: Aakarsh Jain <aakarsh.jain@samsung.com>
> ---
> .../media/platform/samsung/s5p-mfc/s5p_mfc_opr_v6.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 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..03c957221fc4 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
> @@ -498,8 +498,8 @@ static void s5p_mfc_dec_calc_dpb_size_v6(struct s5p_mfc_ctx *ctx)
> case V4L2_PIX_FMT_NV21M:
> ctx->stride[0] = ALIGN(ctx->img_width, S5P_FIMV_NV12MT_HALIGN_V6);
> ctx->stride[1] = ALIGN(ctx->img_width, S5P_FIMV_NV12MT_HALIGN_V6);
> - ctx->luma_size = calc_plane(ctx->stride[0], ctx->img_height);
> - ctx->chroma_size = calc_plane(ctx->stride[1], (ctx->img_height / 2));
> + ctx->luma_size = calc_plane(ctx->img_width, ctx->img_height);
> + ctx->chroma_size = calc_plane(ctx->img_width, (ctx->img_height >> 1));

These size needs to match the sizes reported through TRY_FMT (and S_FMT)
sizeimage for each planes. Is this code being call withing try_fmt ? Will these
value match or will this change cause the value to miss-match ?

The reason is that correct value is needed for allocating this memory from the
outside (like using a DMAbuf Heap). Perhaps its all right, let me know.

Nicolas

> break;
> case V4L2_PIX_FMT_YUV420M:
> case V4L2_PIX_FMT_YVU420M:
> @@ -539,9 +539,11 @@ static void s5p_mfc_dec_calc_dpb_size_v6(struct s5p_mfc_ctx *ctx)
> static void s5p_mfc_enc_calc_src_size_v6(struct s5p_mfc_ctx *ctx)
> {