Re: [Intel-gfx] [PATCH v3 2/5] drm/i915/dg2: Add Wa_14010547955

[Clint Taylor <Clinton.A.Taylor@intel.com>]

Looks correct.

Reviewed-by: Clint Taylor <Clinton.A.Taylor@intel.com>

-Clint


On 11/16/21 9:48 AM, Matt Roper wrote:
> This workaround is documented a bit strangely in the bspec; it's listed
> as an A0 workaround, but the description clarifies that the workaround
> is implicitly handled by the hardware and what the driver really needs
> to do is program a chicken bit to reenable some internal behavior.
>
> Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> ---
>   drivers/gpu/drm/i915/display/intel_display.c | 4 ++++
>   drivers/gpu/drm/i915/i915_reg.h              | 5 +++--
>   2 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 0ceee8ac6671..1639bdbe2091 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -988,6 +988,10 @@ static void icl_set_pipe_chicken(const struct intel_crtc_state *crtc_state)
>   	else if (DISPLAY_VER(dev_priv) >= 13)
>   		tmp |= UNDERRUN_RECOVERY_DISABLE_ADLP;
>   
> +	/* Wa_14010547955:dg2 */
> +	if (IS_DG2_DISPLAY_STEP(dev_priv, STEP_B0, STEP_FOREVER))
> +		tmp |= DG2_RENDER_CCSTAG_4_3_EN;
> +
>   	intel_de_write(dev_priv, PIPE_CHICKEN(pipe), tmp);
>   }
>   
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index f15ffc53e858..c187ec122fdb 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -8568,8 +8568,9 @@ enum {
>   							   _PIPEB_CHICKEN)
>   #define   UNDERRUN_RECOVERY_DISABLE_ADLP	REG_BIT(30)
>   #define   UNDERRUN_RECOVERY_ENABLE_DG2		REG_BIT(30)
> -#define   PIXEL_ROUNDING_TRUNC_FB_PASSTHRU 	(1 << 15)
> -#define   PER_PIXEL_ALPHA_BYPASS_EN		(1 << 7)
> +#define   PIXEL_ROUNDING_TRUNC_FB_PASSTHRU	REG_BIT(15)
> +#define   DG2_RENDER_CCSTAG_4_3_EN		REG_BIT(12)
> +#define   PER_PIXEL_ALPHA_BYPASS_EN		REG_BIT(7)
>   
>   #define VFLSKPD				_MMIO(0x62a8)
>   #define   DIS_OVER_FETCH_CACHE		REG_BIT(1)