[PATCH] [v2] drm/i915/pmu: avoid -Wmaybe-uninitialized warning

[Chris Wilson]

Quoting Arnd Bergmann (2018-03-13 16:19:31)
> The conditional spinlock confuses gcc into thinking the 'flags' value
> might contain uninitialized data:
> 
> drivers/gpu/drm/i915/i915_pmu.c: In function '__i915_pmu_event_read':
> arch/x86/include/asm/paravirt_types.h:573:3: error: 'flags' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> 
> The code is correct, but it's easy to see how the compiler gets confused
> here. This avoids the problem by pulling the lock outside of the function
> into its only caller.
> 
> Fixes: 1fe699e30113 ("drm/i915/pmu: Fix sleep under atomic in RC6 readout")
> Signed-off-by: Arnd Bergmann <arnd at arndb.de>
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris