Re: [PATCH v2 2/4] drm/i915/3dlut: disable 3D LUT for pre-GLK

On 8/4/2026 3:19 AM, Michał Grzelak wrote:
> GLK+ hardware supports 3D LUT. Disable the feature for pre-GLK
> platforms.
> 
> Add .has_3dlut field into struct intel_display_runtime_info. Use the
> field to store whether 3D LUT is enabled. Initialize the field to 1 on
> GLK+.
> 
> Add macro for checking 3D LUT's support. Use it while checking whether
> CRTC has 3D LUT enabled.
> 
> v1->v2
> - use either runtime info flag or display version check (Jani)
> - don't initialize runtime info flag to 0 (Jani)
> 
> Bspec: 15585
> Cc: Chaitanya Kumar Borah <[email protected]>
> Cc: <[email protected]>
> Fixes: 65db7a1f9cf7 ("drm/i915/color: Add 3D LUT to color pipeline")

I am not sure if you need the fixes tag for this patch because 3D LUT is 
already gated on DISPLAY_VER(display) >= 12. More on it on Patch 3.

> Signed-off-by: Michał Grzelak <[email protected]>
> ---
>   drivers/gpu/drm/i915/display/intel_color.c          | 3 +++
>   drivers/gpu/drm/i915/display/intel_display_device.c | 5 +++++
>   drivers/gpu/drm/i915/display/intel_display_device.h | 2 ++
>   3 files changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
> index 87ced9f6ff40..ffdefb51a264 100644
> --- a/drivers/gpu/drm/i915/display/intel_color.c
> +++ b/drivers/gpu/drm/i915/display/intel_color.c
> @@ -4258,6 +4258,9 @@ intel_color_load_plane_luts(struct intel_dsb *dsb,
>   bool
>   intel_color_crtc_has_3dlut(struct intel_display *display, enum pipe pipe)
>   {
> +	if (!HAS_3DLUT(display))
> +		return false;
> +
>   	if (DISPLAY_VER(display) >= 12)
>   		return pipe == PIPE_A || pipe == PIPE_B;
>   	else
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c b/drivers/gpu/drm/i915/display/intel_display_device.c
> index f17fc2c68472..4c09f35644ba 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.c
> @@ -864,6 +864,7 @@ static const struct platform_desc glk_desc = {
>   		GLK_COLORS,
>   
>   		.__runtime_defaults.ip.ver = 10,
> +		.__runtime_defaults.has_3dlut = 1,
>   	},
>   	STEP_INFO(glk_steppings),
>   };
> @@ -899,6 +900,7 @@ static const struct platform_desc glk_desc = {
>   	ICL_COLORS, \
>   	\
>   	.__runtime_defaults.ip.ver = 11, \
> +	.__runtime_defaults.has_3dlut = 1, \
>   	.__runtime_defaults.has_dmc = 1, \
>   	.__runtime_defaults.has_dsc = 1, \
>   	.__runtime_defaults.has_hdcp = 1, \
> @@ -990,6 +992,7 @@ static const struct platform_desc ehl_desc = {
>   	ICL_COLORS, \
>   	\
>   	.__runtime_defaults.ip.ver = 12, \
> +	.__runtime_defaults.has_3dlut = 1, \
>   	.__runtime_defaults.has_dmc = 1, \
>   	.__runtime_defaults.has_dsc = 1, \
>   	.__runtime_defaults.has_hdcp = 1, \
> @@ -1156,6 +1159,7 @@ static const struct platform_desc adl_s_desc = {
>   	TGL_CURSOR_OFFSETS,							\
>   										\
>   	.__runtime_defaults.ip.ver = 13,					\
> +	.__runtime_defaults.has_3dlut = 1,					\
>   	.__runtime_defaults.has_dmc = 1,					\
>   	.__runtime_defaults.has_dsc = 1,					\
>   	.__runtime_defaults.fbc_mask = BIT(INTEL_FBC_A),			\
> @@ -1335,6 +1339,7 @@ static const struct platform_desc dg2_desc = {
>   		BIT(TRANSCODER_A) | BIT(TRANSCODER_B) |				\
>   		BIT(TRANSCODER_C) | BIT(TRANSCODER_D),				\
>   	.__runtime_defaults.fbc_mask = BIT(INTEL_FBC_A) | BIT(INTEL_FBC_B),	\
> +	.__runtime_defaults.has_3dlut = 1,					\
>   	.__runtime_defaults.has_dmc = 1,					\
>   	.__runtime_defaults.has_dsc = 1,					\
>   	.__runtime_defaults.has_hdcp = 1,					\
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.h b/drivers/gpu/drm/i915/display/intel_display_device.h
> index 7121e7cd9512..5300c6ab99e7 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.h
> @@ -147,6 +147,7 @@ struct intel_display_platforms {
>   
>   #define HAS_128B_Y_TILING(__display)	(!(__display)->platform.i915g && !(__display)->platform.i915gm)
>   #define HAS_2PPC(__display)		(DISPLAY_VER(__display) >= 10)
> +#define HAS_3DLUT(__display)		(DISPLAY_RUNTIME_INFO(__display)->has_3dlut)
>   #define HAS_4TILE(__display)		((__display)->platform.dg2 || DISPLAY_VER(__display) >= 14)
>   #define HAS_ASYNC_FLIPS(__display)	(DISPLAY_VER(__display) >= 5)
>   #define HAS_AS_SDP(__display)		(DISPLAY_VER(__display) >= 13)
> @@ -304,6 +305,7 @@ struct intel_display_runtime_info {
>   
>   	u8 fbc_mask;
>   
> +	bool has_3dlut;
>   	bool has_hdcp;
>   	bool has_dmc;
>   	bool has_dsc;