Quoting Pankaj Bharadiya (2020-02-25 13:47:00)
Now that we have struct drm_device based drm_WARN, introduce struct drm_i915_private based i915_MISSING_CASE macro which uses drm_WARN so that device specific information will also get printed in backtrace.
i915_MISSING_CASE macro should be preferred over MISSING_CASE, wherever possible.
Whatever for? MISSING_CASE() itself should be a complete picture for the forgotten code. -Chris