Re: [igt-dev] [PATCH i-g-t 1/2] lib/i915/intel_memory_region: Provide system memory region stub

["Dixit, Ashutosh" <ashutosh.dixit@intel.com>]

On Thu, 09 Dec 2021 12:04:52 -0800, Zbigniew Kempczyński wrote:
>
> diff --git a/lib/i915/intel_memory_region.c b/lib/i915/intel_memory_region.c
> index 058b273dc..fd29eec90 100644
> --- a/lib/i915/intel_memory_region.c
> +++ b/lib/i915/intel_memory_region.c
> @@ -123,9 +123,17 @@ struct drm_i915_query_memory_regions *gem_get_query_memory_regions(int fd)
>	 * Any DRM_I915_QUERY_MEMORY_REGIONS specific errors are encoded in the
>	 * item.length, even though the ioctl might still return success.
>	 */
> +
>	if (item.length < 0) {
> -		igt_critical("DRM_I915_QUERY_MEMORY_REGIONS failed with %d\n",
> -			     item.length);
> +		/*
> +		 * If kernel supports query but not memory regions query
> +		 * just return predefined system memory region only.
> +		 */
> +		size_t sys_qi_size = offsetof(typeof(*query_info), regions[1]);
> +
> +		query_info = calloc(1, sys_qi_size);
> +		query_info->num_regions = 1;
> +		query_info->regions[0].region.memory_class = I915_MEMORY_CLASS_SYSTEM;

Should there be another check here that DRM_I915_QUERY_MEMORY_REGIONS query
was not recognized? Otherwise the query could have failed for some other
reason?