Re: [Intel-gfx] [PATCH 2/3] drm/i915/guc: Fix a static analysis warning

["Ceraolo Spurio, Daniele" <daniele.ceraolospurio@intel.com>]

Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>

Daniele

On 12/21/2022 8:30 PM, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
>
> A static analyser was complaining about not checking for null
> pointers. However, the location of the complaint can only be reached
> in the first place if said pointer is non-null. Basically, if we are
> using a v69 GuC then the descriptor pool is guaranteed to be alocated
> at start of day or submission will be disabled with an ENOMEM error.
> And if we are using a later GuC that does not use a descriptor pool
> then the v69 submission function would not be called. So, not a
> possible null at that point in the code.
>
> Hence adding a GEM_BUG_ON(!ptr) to keep the tool happy.
>
> Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
> ---
>   drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> index 4682ec1dbd9c0..c93d0594bfd5e 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> @@ -2538,6 +2538,7 @@ static void prepare_context_registration_info_v69(struct intel_context *ce)
>   		   i915_gem_object_is_lmem(ce->ring->vma->obj));
>   
>   	desc = __get_lrc_desc_v69(guc, ctx_id);
> +	GEM_BUG_ON(!desc);
>   	desc->engine_class = engine_class_to_guc_class(engine->class);
>   	desc->engine_submit_mask = engine->logical_mask;
>   	desc->hw_context_desc = ce->lrc.lrca;