Re: [PATCH v2 4/4] drm/i915/dg2: Implement Wa_14022698537

["Nilawar, Badal" <badal.nilawar@intel.com>]

On 11-10-2024 16:02, Raag Jadav wrote:
> G8 power state entry is disabled due to a limitation on DG2, so we
> enable it from driver with Wa_14022698537. Fow now we enable it for
> all DG2 devices with the exception of a few, for which, we enable
> only when paired with whitelisted CPU models.
> 
> v2: Fix Wa_ID and include it in subject (Badal)
>      Rephrase commit message (Jani)
> 
> Signed-off-by: Raag Jadav <raag.jadav@intel.com>
> ---
>   drivers/gpu/drm/i915/gt/intel_workarounds.c | 18 ++++++++++++++++++
>   drivers/gpu/drm/i915/i915_reg.h             |  1 +
>   2 files changed, 19 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> index e539a656cfc3..bcd7630c1631 100644
> --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> @@ -14,6 +14,7 @@
>   #include "intel_gt_mcr.h"
>   #include "intel_gt_print.h"
>   #include "intel_gt_regs.h"
> +#include "intel_pcode.h"
>   #include "intel_ring.h"
>   #include "intel_workarounds.h"
>   
> @@ -1770,9 +1771,26 @@ static void wa_list_apply(const struct i915_wa_list *wal)
>   	intel_gt_mcr_unlock(gt, flags);
>   }
>   
> +/* Wa_14022698537:dg2 */
> +static void intel_enable_g8(struct intel_uncore *uncore)
> +{
> +	struct drm_i915_private *i915 = uncore->i915;
> +
> +	if (IS_DG2(i915)) {
> +		if (IS_DG2_WA(i915) && !intel_match_wa_cpu())
> +			return;
> +
> +		snb_pcode_write_p(uncore, PCODE_POWER_SETUP,
> +				  POWER_SETUP_SUBCOMMAND_G8_ENABLE, 0, 0);
> +	}
> +}
> +
>   void intel_gt_apply_workarounds(struct intel_gt *gt)
>   {
>   	wa_list_apply(&gt->wa_list);
> +
> +	/* Special case for pcode mailbox which can't be on wa_list */
> +	intel_enable_g8(gt->uncore);

This workaround is not specific to GT; G8 is a state specific to the 
SoC. Therefore, move this workaround above the GT layer and pass 
argument i915->uncore instead of gt->uncore

Regards,
Badal

>   }
>   
>   static bool wa_list_verify(struct intel_gt *gt,
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 41f4350a7c6c..e948b194550c 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -3568,6 +3568,7 @@
>   #define   PCODE_POWER_SETUP			0x7C
>   #define     POWER_SETUP_SUBCOMMAND_READ_I1	0x4
>   #define     POWER_SETUP_SUBCOMMAND_WRITE_I1	0x5
> +#define     POWER_SETUP_SUBCOMMAND_G8_ENABLE	0x6
>   #define	    POWER_SETUP_I1_WATTS		REG_BIT(31)
>   #define	    POWER_SETUP_I1_SHIFT		6	/* 10.6 fixed point format */
>   #define	    POWER_SETUP_I1_DATA_MASK		REG_GENMASK(15, 0)