[Intel-gfx] [PATCH] drm: avoid "possible bad bitmask?" warning

[Chris Wilson]

On Tue, Aug 09, 2016 at 06:35:10PM +0100, Dave Gordon wrote:
> Recent versions of gcc say this:
> 
> include/drm/i915_drm.h:96:34: warning: result of ‘65535 << 20’
> requires 37 bits to represent, but ‘int’ only has 32 bits
> [-Wshift-overflow=]
> 
> Reported-by: David Binderman <linuxdev.baldrick at gmail.com>
> Signed-off-by: Dave Gordon <david.s.gordon at intel.com>
> Cc: Dave Airlie <airlied at gmail.com>
> ---
>  include/drm/i915_drm.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
> index b1755f8..4e1b274 100644
> --- a/include/drm/i915_drm.h
> +++ b/include/drm/i915_drm.h
> @@ -93,6 +93,6 @@ extern bool i915_gpu_turbo_disable(void);
>  #define    I845_TSEG_SIZE_1M	(3 << 1)
>  
>  #define INTEL_BSM 0x5c
> -#define   INTEL_BSM_MASK (0xFFFF << 20)
> +#define   INTEL_BSM_MASK	(-(1u << 20))

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre