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

[Lucas De Marchi]

On Thu, Sep 21, 2023 at 08:23:52PM +0300, Ville Syrjälä wrote:
>On Thu, Sep 21, 2023 at 08:22:23AM -0500, Lucas De Marchi wrote:
>> 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.
>
>Well, we care what it actually means. If the bspec and hardware reported
>IP version all messed up how is one supposed to know what hardware has what
>features?

Bspec says LNL has Display IP version 20.

IP is called Xe2-LPD. Version is 20. In some places in the spec there
are mentions to the old name. Someone probably needs to do a search and
replace, but that is beyond what I can do. The version was never 15,
that was part of the name.

If you want to add a new source of confusion, in some places version is
(was? can't find them anymore) marked in bspec as 0x14 so we had some
early patches checking version 14 rather than 20 by mistake. None of the
patches being upstreamed should have them anymore though.

Lucas De Marchi

>
>-- 
>Ville Syrjälä
>Intel