[Intel-gfx] [PATCH] drm/i915/dg2: Add workaround 22014600077

[Matt Roper]

On Tue, May 17, 2022 at 11:02:01AM -0700, Swathi Dhanavanthri wrote:
> Bspec: 45810,54077,68173
> 
> Signed-off-by: Swathi Dhanavanthri <swathi.dhanavanthri at intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_gt_regs.h     | 1 +
>  drivers/gpu/drm/i915/gt/intel_workarounds.c | 9 +++++++++
>  2 files changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> index 98ede9c93f00..2063c8758934 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> @@ -1068,6 +1068,7 @@
>  #define   GEN9_ENABLE_GPGPU_PREEMPTION		REG_BIT(2)
>  
>  #define GEN10_CACHE_MODE_SS			_MMIO(0xe420)
> +#define   ENABLE_EU_COUNT_FOR_TDL_FLUSH	        REG_BIT(10)

I think this line has some spaces before REG_BIT().  We should only be
using tabs between the variable name and the 'REG_BIT.'

>  #define   ENABLE_PREFETCH_INTO_IC		REG_BIT(3)
>  #define   FLOAT_BLEND_OPTIMIZATION_ENABLE	REG_BIT(4)
>  
> diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> index 756807c4b405..c647a9e48389 100644
> --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> @@ -2178,6 +2178,15 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal)
>  		wa_write_or(wal, GEN12_MERT_MOD_CTRL, FORCE_MISS_FTLB);
>  	}
>  
> +	if (IS_DG2_GRAPHICS_STEP(i915, G11, STEP_B0, STEP_FOREVER) ||
> +	    IS_DG2_G10(i915)) {
> +		/* Wa_22014600077:dg2 */
> +		wa_add(wal, GEN10_CACHE_MODE_SS, 0,
> +		       _MASKED_BIT_ENABLE(ENABLE_EU_COUNT_FOR_TDL_FLUSH),
> +		       0 /* write-only, so skip validation */,

The fact that this register is WO is itself a different workaround, so
you may want to reference that in the comment.  E.g.,

        0 /* Wa_14012342262: write-only reg, skip verification */


Matt

> +		       true);
> +	}
> +
>  	if (IS_DG1_GRAPHICS_STEP(i915, STEP_A0, STEP_B0) ||
>  	    IS_TGL_UY_GRAPHICS_STEP(i915, STEP_A0, STEP_B0)) {
>  		/*
> -- 
> 2.20.1
> 

-- 
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation