Re: [PATCH 3/3] drm/i915/display: add HAS_AUX_CCS() feature check

[Jani Nikula <jani.nikula@intel.com>]

On Fri, 10 Oct 2025, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote:
> On Fri, Oct 10, 2025 at 02:07:53PM +0300, Jani Nikula wrote:
>> We should try to get rid of checks that depend on struct
>> drm_i915_private (or struct xe_device) in display code. HAS_FLAT_CCS()
>> is one of them. In the interest of simplicity, add a reversed
>> HAS_AUX_CCS() feature check macro, as that's we mostly use it for in
>> display.
>> 
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>> 
>> ---
>> 
>> Is "display < 13 || mtl" good enough?
>> ---
>>  drivers/gpu/drm/i915/display/intel_display_device.h | 1 +
>>  drivers/gpu/drm/i915/display/intel_fb.c             | 4 +---
>>  drivers/gpu/drm/i915/display/skl_universal_plane.c  | 4 ++--
>>  drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h   | 2 --
>>  4 files changed, 4 insertions(+), 7 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.h b/drivers/gpu/drm/i915/display/intel_display_device.h
>> index 9960ac13a6dd..3ceecfe3b1b7 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display_device.h
>> +++ b/drivers/gpu/drm/i915/display/intel_display_device.h
>> @@ -144,6 +144,7 @@ struct intel_display_platforms {
>>  
>>  #define HAS_128B_Y_TILING(__display)	(!(__display)->platform.i915g && !(__display)->platform.i915gm)
>>  #define HAS_4TILE(__display)		((__display)->platform.dg2 || DISPLAY_VER(__display) >= 14)
>> +#define HAS_AUX_CCS(__display)		(DISPLAY_VER(__display) < 13 || (__display)->platform.meteorlake)
>
> That is missing ADL.

D'oh.

> I think we'd need
>  IS_DISPLAY_VER(9, 12) || adl || mtl
> or
>  IS_DISPLAY_VER(9, 14) && !dg2 && !bmg
>
> Dunno which is uglier.
>
> I was first thinking the latter could just be 
> 'IS_DISPLAY_VER(9, 14) && !IS_DGFX' but looks like we don't have
> IS_DFGX in the display code anymore, and also that would be wrong
> for DG1 (assuming we'd say IS_DGFX==true for it).

We now have the "platform groups" in display->platform, including
display->platform.dgfx. But I opted to go for including adl-p.

BR,
Jani.

>
>>  #define HAS_ASYNC_FLIPS(__display)	(DISPLAY_VER(__display) >= 5)
>>  #define HAS_AS_SDP(__display)		(DISPLAY_VER(__display) >= 13)
>>  #define HAS_BIGJOINER(__display)	(DISPLAY_VER(__display) >= 11 && HAS_DSC(__display))
>> diff --git a/drivers/gpu/drm/i915/display/intel_fb.c b/drivers/gpu/drm/i915/display/intel_fb.c
>> index 7388791dfde0..9c256a2805e4 100644
>> --- a/drivers/gpu/drm/i915/display/intel_fb.c
>> +++ b/drivers/gpu/drm/i915/display/intel_fb.c
>> @@ -547,8 +547,6 @@ static bool plane_has_modifier(struct intel_display *display,
>>  			       u8 plane_caps,
>>  			       const struct intel_modifier_desc *md)
>>  {
>> -	struct drm_i915_private *i915 = to_i915(display->drm);
>> -
>>  	if (!IS_DISPLAY_VER(display, md->display_ver.from, md->display_ver.until))
>>  		return false;
>>  
>> @@ -560,7 +558,7 @@ static bool plane_has_modifier(struct intel_display *display,
>>  	 * where supported.
>>  	 */
>>  	if (intel_fb_is_ccs_modifier(md->modifier) &&
>> -	    HAS_FLAT_CCS(i915) != !md->ccs.packed_aux_planes)
>> +	    HAS_AUX_CCS(display) != !!md->ccs.packed_aux_planes)
>>  		return false;
>>  
>>  	if (md->modifier == I915_FORMAT_MOD_4_TILED_BMG_CCS &&
>> diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c b/drivers/gpu/drm/i915/display/skl_universal_plane.c
>> index e13fb781e7b2..0319174adf95 100644
>> --- a/drivers/gpu/drm/i915/display/skl_universal_plane.c
>> +++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c
>> @@ -1572,7 +1572,7 @@ icl_plane_update_noarm(struct intel_dsb *dsb,
>>  	}
>>  
>>  	/* FLAT CCS doesn't need to program AUX_DIST */
>> -	if (!HAS_FLAT_CCS(to_i915(display->drm)) && DISPLAY_VER(display) < 20)
>> +	if (HAS_AUX_CCS(display))
>>  		intel_de_write_dsb(display, dsb, PLANE_AUX_DIST(pipe, plane_id),
>>  				   skl_plane_aux_dist(plane_state, color_plane));
>>  
>> @@ -2930,7 +2930,7 @@ skl_universal_plane_create(struct intel_display *display,
>>  		caps = skl_plane_caps(display, pipe, plane_id);
>>  
>>  	/* FIXME: xe has problems with AUX */
>> -	if (!IS_ENABLED(I915) && !HAS_FLAT_CCS(to_i915(display->drm)))
>> +	if (!IS_ENABLED(I915) && HAS_AUX_CCS(display))
>>  		caps &= ~(INTEL_PLANE_CAP_CCS_RC |
>>  			  INTEL_PLANE_CAP_CCS_RC_CC |
>>  			  INTEL_PLANE_CAP_CCS_MC);
>> diff --git a/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h b/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h
>> index be3edf20de22..7c657ea98a44 100644
>> --- a/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h
>> +++ b/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h
>> @@ -35,6 +35,4 @@ static inline struct drm_i915_private *to_i915(const struct drm_device *dev)
>>  
>>  #define IS_MOBILE(xe) (xe && 0)
>>  
>> -#define HAS_FLAT_CCS(xe) (xe_device_has_flat_ccs(xe))
>> -
>>  #endif
>> -- 
>> 2.47.3

-- 
Jani Nikula, Intel