Re: [PATCH v2] drm/i915/fbc: update the impacted platforms in wa_22014263786

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

On Wed, 01 Oct 2025, Vinod Govindapillai <vinod.govindapillai@intel.com> wrote:
> wa_22014263786 is not applicable to the BMG and hence exclude it
> from the wa.
>
> v2: Limit this wa to display verion 11 to 14, drop DG2 from the
>     exclusion list, use intel_display_wa (Lucas)
>
> Bspec: 74212, 66624
> Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display_wa.c | 12 ++++++++++++
>  drivers/gpu/drm/i915/display/intel_display_wa.h |  1 +
>  drivers/gpu/drm/i915/display/intel_fbc.c        |  3 +--
>  3 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_wa.c b/drivers/gpu/drm/i915/display/intel_display_wa.c
> index 31cd2c9cd488..7ca238725e30 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_wa.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_wa.c
> @@ -52,6 +52,16 @@ static bool intel_display_needs_wa_16025573575(struct intel_display *display)
>  	return DISPLAY_VERx100(display) == 3000 || DISPLAY_VERx100(display) == 3002;
>  }
>  
> +/*
> + * Wa_22014263786:
> + * Fixes: Screen flicker with FBC and Package C state enabled
> + * Workaround: Forced SLB invalidation before start of new frame.
> + */
> +static bool intel_display_needs_wa_22014263786(struct intel_display *display)
> +{
> +	return DISPLAY_VERx100(display) >= 1100 && DISPLAY_VERx100(display) < 1401;

IS_DISPLAY_VERx100(display, 1100, 1400)

Also I'm not sure if we really need separate functions for one-liners
like this. The documentation could be in the switch case too? *shrug*.

BR,
Jani.

> +}
> +
>  /*
>   * Wa_14011503117:
>   * Fixes: Before enabling the scaler DE fatal error is masked
> @@ -67,6 +77,8 @@ bool __intel_display_wa(struct intel_display *display, enum intel_display_wa wa,
>  		return intel_display_needs_wa_16025573575(display);
>  	case INTEL_DISPLAY_WA_14011503117:
>  		return DISPLAY_VER(display) == 13;
> +	case INTEL_DISPLAY_WA_22014263786:
> +		return intel_display_needs_wa_22014263786(display);
>  	default:
>  		drm_WARN(display->drm, 1, "Missing Wa number: %s\n", name);
>  		break;
> diff --git a/drivers/gpu/drm/i915/display/intel_display_wa.h b/drivers/gpu/drm/i915/display/intel_display_wa.h
> index abc1df83f066..3644e8e2b724 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_wa.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_wa.h
> @@ -25,6 +25,7 @@ enum intel_display_wa {
>  	INTEL_DISPLAY_WA_16023588340,
>  	INTEL_DISPLAY_WA_16025573575,
>  	INTEL_DISPLAY_WA_14011503117,
> +	INTEL_DISPLAY_WA_22014263786,
>  };
>  
>  bool __intel_display_wa(struct intel_display *display, enum intel_display_wa wa, const char *name);
> diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
> index 0d380c825791..9607fdcb0cc0 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbc.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbc.c
> @@ -933,8 +933,7 @@ static void intel_fbc_program_workarounds(struct intel_fbc *fbc)
>  		intel_de_rmw(display, ILK_DPFC_CHICKEN(fbc->id),
>  			     0, DPFC_CHICKEN_COMP_DUMMY_PIXEL);
>  
> -	/* Wa_22014263786:icl,jsl,tgl,dg1,rkl,adls,adlp,mtl */
> -	if (DISPLAY_VER(display) >= 11 && !display->platform.dg2)
> +	if (intel_display_wa(display, 22014263786))
>  		intel_de_rmw(display, ILK_DPFC_CHICKEN(fbc->id),
>  			     0, DPFC_CHICKEN_FORCE_SLB_INVALIDATION);

-- 
Jani Nikula, Intel