[Intel-gfx] [PATCH v2] drm/i915: Prevent unbounded wm results in g4x_compute_wm()

[Chris Wilson]

Quoting Chris Wilson (2017-11-07 14:03:38)
> Smatch warns of
> 
> drivers/gpu/drm/i915/intel_pm.c:1161 g4x_compute_wm() warn: signedness bug returning '(-33554430)'
> 
> which is a result of it believing that wm may be INT_MAX following
> g4x_tlb_miss_wa(). Just declaring g4x_tlb_miss_wa() as returning an
> unsigned integer is not sufficient, we need to tell smatch that wm itself
> is unsigned for it to not worry. So mark up the locals we expect to be
> non-negative, and so silence smatch.
> 
> v2: Mark up vlv_compute_intermediate_wm() as unsigned similarly.
s/vlv_compute_intermediate_vm/vlv_compute_wm_level/
-Chris