[Intel-gfx] [PATCH] drm/i915: Use BUILD_BUG_ON to detected missing engine definitions

[Chris Wilson]

On Tue, Feb 28, 2017 at 02:00:50PM +0000, Michal Wajdeczko wrote:
> Additionally use runtime check to catch invalid engine indices.

Oh no you don't!
 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_engine_cs.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
> index a238304..8df53ae 100644
> --- a/drivers/gpu/drm/i915/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/intel_engine_cs.c
> @@ -89,6 +89,8 @@ intel_engine_setup(struct drm_i915_private *dev_priv,
>  	const struct engine_info *info = &intel_engines[id];
>  	struct intel_engine_cs *engine;
>  
> +	BUILD_BUG_ON(ARRAY_SIZE(intel_engines) != I915_NUM_ENGINES);
> +	GEM_BUG_ON(id < 0 || id >= I915_NUM_ENGINES);

Are you sure sparse/smatch won't complain?
/me too lazy to check the C standard for signedness of an enum without a
negative value.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre