[Intel-gfx] [PATCH] drm/i915: Reword warning for missing cases

[Chris Wilson]

Quoting Lucas De Marchi (2018-03-13 00:03:12)
> In some places we end up converting switch statements to a series of
> if/else, particularly when introducing helper functions to handle a
> group of cases. It's tempting to either leave a wrong warning (since now
> we don't have a switch case anymore) or to convert to WARN(1, ...),
> losing what MISSING_CASE() provides: source location and id number.
> 
> Fix the message to allow reusing MISSING_CASE() - it may not always be
> correct (e.g. if you are not checking an id anymore), but it avoids
> useless conversions. A quick grep reveals at least a few users in
> drivers/gpu/drm/i915/intel_csr.c and drivers/gpu/drm/i915/intel_ddi.c.
> 
> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_utils.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h
> index 51dbfe5bb418..8cdc21b92f5f 100644
> --- a/drivers/gpu/drm/i915/i915_utils.h
> +++ b/drivers/gpu/drm/i915/i915_utils.h
> @@ -40,7 +40,7 @@
>  #undef WARN_ON_ONCE
>  #define WARN_ON_ONCE(x) WARN_ONCE((x), "%s", "WARN_ON_ONCE(" __stringify(x) ")")
>  
> -#define MISSING_CASE(x) WARN(1, "Missing switch case (%lu) in %s\n", \
> +#define MISSING_CASE(x) WARN(1, "Missing case (%lu) in %s\n", \
>                              (long)(x), __func__)

Whilst here you could make this more informative by:
"Missing case (%s = %lu) in %s\n", __stringify(x), (long)(x), __func__

Also these should only be compiled for dev/CI as we have a few pages
worth of them.
-Chris