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

[Ville Syrjälä]

On Thu, Sep 21, 2023 at 08:34:35AM +0000, Govindapillai, Vinod wrote:
> On Wed, 2023-09-13 at 13:38 +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.
> > 
> > > +           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.
> 
> Hi,
> 
> Could you please clarify this.

pixel_format_is_valid()

-- 
Ville Syrjälä
Intel