Messages in this thread | | | Subject | Re: [Intel-gfx] include/drm/i915_drm.h:96: possible bad bitmask ? | From | Dave Gordon <> | Date | Tue, 9 Aug 2016 17:01:15 +0100 |
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On 09/08/16 03:59, Dave Airlie wrote: > On 8 August 2016 at 19:40, Daniel Vetter <daniel@ffwll.ch> wrote: >> On Mon, Aug 08, 2016 at 10:31:32AM +0100, David Binderman wrote: >>> Hello there, >>> >>> 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=] >>> >>> Source code is >>> >>> #define INTEL_BSM_MASK (0xFFFF << 20) >>> >>> Maybe something like >>> >>> #define INTEL_BSM_MASK (0xFFFFUL<< 20) >>> >>> might be better. >> >> Yup. Care to bake this into a patch (with s-o-b and everything per >> Documentation/SubmittingPatches) so I can apply it? > > Why would you want to apply a clearly incorrect patch :-) > > INTEL_BSM_MASK is used in one place, on a 32-bit number > > I'm not sure what it needs to be, but a 64-bit number it doesn't. > > Dave.
I found two uses, but in both cases it's masking a value read from a 32-bit PCI register, so it can just be (-(1 << 20)).
.Dave.
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