[Intel-gfx] [PATCH v1 1/1] drm/i915/xe2lpd: alternate WA for underruns with PSR2 and FBC

[Govindapillai, Vinod]

Hi,


On Fri, 2023-11-03 at 11:21 +0200, Jani Nikula wrote:
> On Fri, 03 Nov 2023, Vinod Govindapillai <vinod.govindapillai at intel.com> wrote:
> > Implement the alternate WA for the underruns when both PSR2
> > and FBC is enabled.
> 
> But we don't enable FBC when PSR2 is enabled, for display 12+.
> 
> See intel_fbc.c line 1200 or so.

Yes. I had another series to enable FBC + PSR for xe2lpd.
https://patchwork.freedesktop.org/series/125932/
I should mention that here.


Thanks
Vinod

> 
> BR,
> Jani.
> 
> 
> > 
> > Signed-off-by: Vinod Govindapillai <vinod.govindapillai at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_fbc.c | 12 +++++++++++-
> >  1 file changed, 11 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
> > index bde12fe62275..b9cd92a997cd 100644
> > --- a/drivers/gpu/drm/i915/display/intel_fbc.c
> > +++ b/drivers/gpu/drm/i915/display/intel_fbc.c
> > @@ -608,6 +608,7 @@ static u32 ivb_dpfc_ctl(struct intel_fbc *fbc)
> >  static void ivb_fbc_activate(struct intel_fbc *fbc)
> >  {
> >         struct drm_i915_private *i915 = fbc->i915;
> > +       u32 dpfc_ctl;
> >  
> >         if (DISPLAY_VER(i915) >= 10)
> >                 glk_fbc_program_cfb_stride(fbc);
> > @@ -617,8 +618,17 @@ static void ivb_fbc_activate(struct intel_fbc *fbc)
> >         if (intel_gt_support_legacy_fencing(to_gt(i915)))
> >                 snb_fbc_program_fence(fbc);
> >  
> > +       /*
> > +        * Alternate WA for HW bug with PSR2 + FBC.
> > +        * 1.Write FBC_CTL with Plane binding set correctly with FBC enable = 0
> > +        * 2.Write FBC_CTL with Plane binding set correctly with FBC enable = 1
> > +        */
> > +       dpfc_ctl = ivb_dpfc_ctl(fbc);
> > +       if (DISPLAY_VER(i915) >= 20)
> > +               intel_de_write(i915, ILK_DPFC_CONTROL(fbc->id), dpfc_ctl);
> > +
> >         intel_de_write(i915, ILK_DPFC_CONTROL(fbc->id),
> > -                      DPFC_CTL_EN | ivb_dpfc_ctl(fbc));
> > +                      DPFC_CTL_EN | dpfc_ctl);
> >  }
> >  
> >  static bool ivb_fbc_is_compressing(struct intel_fbc *fbc)
>