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

[Dave Gordon]

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))
 
 #endif				/* _I915_DRM_H_ */
-- 
1.9.1