* include/drm/i915_drm.h:96: possible bad bitmask ?
@ 2016-08-08 9:31 David Binderman
2016-08-08 9:40 ` [Intel-gfx] " Daniel Vetter
0 siblings, 1 reply; 4+ messages in thread
From: David Binderman @ 2016-08-08 9:31 UTC (permalink / raw)
To: daniel.vetter, jani.nikula, David Airlie, dcb314, intel-gfx,
dri-devel, Linux Kernel Mailing List
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.
Regards
David Binderman
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Intel-gfx] include/drm/i915_drm.h:96: possible bad bitmask ?
2016-08-08 9:31 include/drm/i915_drm.h:96: possible bad bitmask ? David Binderman
@ 2016-08-08 9:40 ` Daniel Vetter
2016-08-09 2:59 ` Dave Airlie
0 siblings, 1 reply; 4+ messages in thread
From: Daniel Vetter @ 2016-08-08 9:40 UTC (permalink / raw)
To: David Binderman
Cc: daniel.vetter, jani.nikula, David Airlie, dcb314, intel-gfx,
dri-devel, Linux Kernel Mailing List
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?
-Daniel
>
>
> Regards
>
> David Binderman
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Intel-gfx] include/drm/i915_drm.h:96: possible bad bitmask ?
2016-08-08 9:40 ` [Intel-gfx] " Daniel Vetter
@ 2016-08-09 2:59 ` Dave Airlie
2016-08-09 16:01 ` Dave Gordon
0 siblings, 1 reply; 4+ messages in thread
From: Dave Airlie @ 2016-08-09 2:59 UTC (permalink / raw)
To: David Binderman, Vetter, Daniel, Jani Nikula, David Airlie,
dcb314, intel-gfx, dri-devel, Linux Kernel Mailing List
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.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Intel-gfx] include/drm/i915_drm.h:96: possible bad bitmask ?
2016-08-09 2:59 ` Dave Airlie
@ 2016-08-09 16:01 ` Dave Gordon
0 siblings, 0 replies; 4+ messages in thread
From: Dave Gordon @ 2016-08-09 16:01 UTC (permalink / raw)
To: Dave Airlie, David Binderman, Vetter, Daniel, Jani Nikula,
David Airlie, dcb314, intel-gfx, dri-devel,
Linux Kernel Mailing List
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.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2016-08-08 9:31 include/drm/i915_drm.h:96: possible bad bitmask ? David Binderman
2016-08-08 9:40 ` [Intel-gfx] " Daniel Vetter
2016-08-09 2:59 ` Dave Airlie
2016-08-09 16:01 ` Dave Gordon
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