[Intel-xe] [Intel-gfx] [PATCH v4 2/2] drm/i915/lnl: FBC is supported with per pixel alpha

[Lucas De Marchi]

On Wed, Sep 13, 2023 at 01:38:23PM +0300, Ville Syrjälä wrote:
>On Mon, Sep 04, 2023 at 02:55:17PM +0300, Vinod Govindapillai wrote:
>> For LNL onwards, FBC can be supported on planes with per
>> pixel alpha
>>
>> Bspec: 69560
>> Signed-off-by: Vinod Govindapillai <vinod.govindapillai at intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_fbc.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
>> index a3999ad95a19..c0e4caec03ea 100644
>> --- a/drivers/gpu/drm/i915/display/intel_fbc.c
>> +++ b/drivers/gpu/drm/i915/display/intel_fbc.c
>> @@ -1209,7 +1209,8 @@ static int intel_fbc_check_plane(struct intel_atomic_state *state,
>>  		return 0;
>>  	}
>>
>> -	if (plane_state->hw.pixel_blend_mode != DRM_MODE_BLEND_PIXEL_NONE &&
>> +	if (DISPLAY_VER(i915) < 20 &&
>
>Bspec still says 15. Someone needs to figure this mess out for
>all LNL patches.

The HW reports IP version 20. The name of the IP is "Xe2-LPD (formerly Display_15)".
For checking the display version, we don't care about the name or former
name, we care about what is in the GMD_ID.

Lucas De Marchi

>
>> +	    plane_state->hw.pixel_blend_mode != DRM_MODE_BLEND_PIXEL_NONE &&
>>  	    fb->format->has_alpha) {
>
>We would have already rejected the pixel format earlier, so atm this
>check is redundant.
>
>>  		plane_state->no_fbc_reason = "per-pixel alpha not supported";
>>  		return 0;
>> --
>> 2.34.1
>
>-- 
>Ville Syrjälä
>Intel