Re: [Intel-gfx] [PATCH v3 11/16] drm/i915/guc: Replace check for golden context size

[Matthew Brost <matthew.brost@intel.com>]

On Wed, Feb 16, 2022 at 09:41:42AM -0800, Lucas De Marchi wrote:
> In the other places in this function, guc->ads_map is being protected
> from access when it's not yet set. However the last check is actually
> about guc->ads_golden_ctxt_size been set before.  These checks should
> always match as the size is initialized on the first call to
> guc_prep_golden_context(), but it's clearer if we have a single return
> and check for guc->ads_golden_ctxt_size.
> 
> This is just a readability improvement, no change in behavior.
> 
> Cc: Matt Roper <matthew.d.roper@intel.com>
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: John Harrison <John.C.Harrison@Intel.com>
> Cc: Matthew Brost <matthew.brost@intel.com>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
> Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

Reviewed-by: Matthew Brost <matthew.brost@intel.com>

> ---
>  drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c
> index 0077a63832ad..b739781bd133 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c
> @@ -500,10 +500,10 @@ static int guc_prep_golden_context(struct intel_guc *guc)
>  		addr_ggtt += alloc_size;
>  	}
>  
> -	if (iosys_map_is_null(&guc->ads_map))
> -		return total_size;
> +	/* Make sure current size matches what we calculated previously */
> +	if (guc->ads_golden_ctxt_size)
> +		GEM_BUG_ON(guc->ads_golden_ctxt_size != total_size);
>  
> -	GEM_BUG_ON(guc->ads_golden_ctxt_size != total_size);
>  	return total_size;
>  }
>  
> -- 
> 2.35.1
>