Re: [PATCH v4 09/11] drm/amd/display: don't ignore failure on blend colorop setup

[Harry Wentland <harry.wentland@amd.com>]

On 2026-08-11 12:45, Melissa Wen wrote:
> __set_input_tf_32() can fail on ENOMEM and let the blend transfer
> function setup in an unstable state. Check its return value and only
> enable blend if transfer function was successfully configured.
> 
> Reported-by: Sashiko <sashiko-bot@kernel.org>
> Fixes: 5ed78b44e4e6 ("drm/amd/display: add shaper and blend colorops for 1D Curve Custom LUT")
> Signed-off-by: Melissa Wen <mwen@igalia.com>

Reviewed-by: Harry Wentland <harry.wentland@amd.com>

Harry

> ---
>   .../drm/amd/display/amdgpu_dm/amdgpu_dm_color.c   | 15 ++++++++++-----
>   1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
> index ad67106c6435..c528daefac5e 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
> @@ -1835,7 +1835,7 @@ __set_dm_plane_colorop_blend(struct drm_plane_state *plane_state,
>   	const struct drm_color_lut32 *blend_lut = NULL;
>   	struct drm_device *dev = colorop->dev;
>   	uint32_t blend_size = 0;
> -	int i = 0;
> +	int i = 0, ret;
>   
>   	tf->type = TF_TYPE_BYPASS;
>   	dc_plane_state->cm.flags.bits.blend_enable = 0;
> @@ -1870,8 +1870,10 @@ __set_dm_plane_colorop_blend(struct drm_plane_state *plane_state,
>   		tf->type = TF_TYPE_DISTRIBUTED_POINTS;
>   		tf->tf = default_tf = amdgpu_colorop_tf_to_dc_tf(tf_state->curve_1d_type);
>   		tf->sdr_ref_white_level = SDR_WHITE_LEVEL_INIT_VALUE;
> +		ret = __set_input_tf_32(NULL, tf, blend_lut, blend_size);
> +		if (ret)
> +			return ret;
>   		dc_plane_state->cm.flags.bits.blend_enable = 1;
> -		__set_input_tf_32(NULL, tf, blend_lut, blend_size);
>   	}
>   
>   	if (lut_state && !lut_state->bypass) {
> @@ -1879,13 +1881,16 @@ __set_dm_plane_colorop_blend(struct drm_plane_state *plane_state,
>   		tf->type = TF_TYPE_DISTRIBUTED_POINTS;
>   		tf->tf = default_tf;
>   		tf->sdr_ref_white_level = SDR_WHITE_LEVEL_INIT_VALUE;
> -		dc_plane_state->cm.flags.bits.blend_enable = 1;
>   		blend_lut = __extract_blob_lut32(lut_state->data, &blend_size);
>   		blend_size = blend_lut != NULL ? blend_size : 0;
>   
>   		/* Custom LUT size must be the same as supported size */
> -		if (blend_size == lut_colorop->size)
> -			__set_input_tf_32(NULL, tf, blend_lut, blend_size);
> +		if (blend_size == lut_colorop->size) {
> +			ret = __set_input_tf_32(NULL, tf, blend_lut, blend_size);
> +			if (ret)
> +				return ret;
> +			dc_plane_state->cm.flags.bits.blend_enable = 1;
> +		}
>   	}
>   
>   	return 0;