[Intel-gfx] [PATCH] drm/i915/guc: ADL-N should use the same GuC FW as ADL-S

[Matt Roper]

On Tue, Jun 21, 2022 at 04:30:05PM -0700, Daniele Ceraolo Spurio wrote:
> The only difference between the ADL S and P GuC FWs is the HWConfig
> support. ADL-N does not support HWConfig, so we should use the same
> binary as ADL-S, otherwise the GuC might attempt to fetch a config
> table that does not exist. ADL-N is internally identified as an ADL-P,
> so we need to special-case it in the FW selection code.
> 
> Fixes: 7e28d0b26759 ("drm/i915/adl-n: Enable ADL-N platform")
> Cc: John Harrison <John.C.Harrison at Intel.com>
> Cc: Tejas Upadhyay <tejas.upadhyay at intel.com>
> Cc: Anusha Srivatsa <anusha.srivatsa at intel.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>

Would the config table still get used somehow even though we return
false for ADL-N in has_table()?

Even if it couldn't be used, this change makes the behavior more clear
and explicit.

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>

> ---
>  drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> index d2c5c9367cc4..ef2d10184ee2 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> @@ -162,6 +162,15 @@ __uc_fw_auto_select(struct drm_i915_private *i915, struct intel_uc_fw *uc_fw)
>  	u8 rev = INTEL_REVID(i915);
>  	int i;
>  
> +	/*
> +	 * The only difference between the ADL GuC FWs is the HWConfig support.
> +	 * ADL-N does not support HWConfig, so we should use the same binary as
> +	 * ADL-S, otherwise the GuC might attempt to fetch a config table that
> +	 * does not exist.
> +	 */
> +	if (IS_ADLP_N(i915))
> +		p = INTEL_ALDERLAKE_S;
> +
>  	GEM_BUG_ON(uc_fw->type >= ARRAY_SIZE(blobs_all));
>  	fw_blobs = blobs_all[uc_fw->type].blobs;
>  	fw_count = blobs_all[uc_fw->type].count;
> -- 
> 2.25.1
> 

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