Re: [PATCH] drm/amd/display: Fix wrong bytes-per-pixel value for dml2_422_packed_10

[george.zhang@amd.com]

On 8/20/26 5:59 AM, Srinivasan Shanmugam <srinivasan.shanmugam@amd.com> wrote:
> The pixel format dml2_422_packed_10 needs BytePerPixelDETY set to
> 8.0/3. But it was accidentally placed in the wrong group that sets it to
>    4, so the correct value was never used.
> 
> This caused wrong DET buffer size and bandwidth calculations whenever
> this format was used.
> 
> Fix it by moving dml2_422_packed_10 out of the wrong group so it gets
> the correct value of 8.0/3.
> 
> Fixes: 04d9a88decbc ("drm/amd/display: Add new sources for DCN6")
> Reported-by: Dan Carpenter <error27@gmail.com>
> Cc: Roman Li <roman.li@amd.com>
> Cc: Alex Hung <alex.hung@amd.com>
> Cc: Tom Chung <chiahsuan.chung@amd.com>
> Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>

Reviewed-by: George Zhang <george.zhang@amd.com>

> ---
>   .../dml2_0/dml21/src/dml2_core/dml2_core_dcn5_calcs_dchub.c   | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/dml2_0/dml21/src/dml2_core/dml2_core_dcn5_calcs_dchub.c b/drivers/gpu/drm/amd/display/dc/dml2_0/dml21/src/dml2_core/dml2_core_dcn5_calcs_dchub.c
> index 321a29d289b6..bd2494c976ac 100644
> --- a/drivers/gpu/drm/amd/display/dc/dml2_0/dml21/src/dml2_core/dml2_core_dcn5_calcs_dchub.c
> +++ b/drivers/gpu/drm/amd/display/dc/dml2_0/dml21/src/dml2_core/dml2_core_dcn5_calcs_dchub.c
> @@ -74,7 +74,9 @@ void dcn5_calculate_byte_per_pixel_and_block_sizes(
>   		*BytePerPixelDETC = 0;
>   		*BytePerPixelY = 8;
>   		*BytePerPixelC = 0;
> -	} else if (SourcePixelFormat == dml2_444_32 || SourcePixelFormat == dml2_rgbe || SourcePixelFormat == dml2_422_packed_10 || SourcePixelFormat == dml2_422_packed_12) {
> +	} else if (SourcePixelFormat == dml2_444_32 ||
> +		   SourcePixelFormat == dml2_rgbe ||
> +		   SourcePixelFormat == dml2_422_packed_12) {
>   		*BytePerPixelDETY = 4;
>   		*BytePerPixelDETC = 0;
>   		*BytePerPixelY = 4;
>