[Intel-gfx] [PATCH RESEND 1/2] drm/i915: make device info bitfield flags bools

Tvrtko Ursulin tvrtko.ursulin at linux.intel.com
Fri May 13 15:05:49 UTC 2016


On 13/05/16 15:47, Jani Nikula wrote:
> On Fri, 13 May 2016, Chris Wilson <chris at chris-wilson.co.uk> wrote:
>> On Fri, May 13, 2016 at 03:25:05PM +0100, Tvrtko Ursulin wrote:
>>>
>>> On 13/05/16 15:04, Jani Nikula wrote:
>>>> This is more robust for assignments and comparisons.
>>>>
>>>> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>>>> ---
>>>>   drivers/gpu/drm/i915/i915_drv.h | 2 +-
>>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>>>> index d9d07b70f05c..bb0b6f64000e 100644
>>>> --- a/drivers/gpu/drm/i915/i915_drv.h
>>>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>>>> @@ -752,7 +752,7 @@ struct intel_csr {
>>>>   	func(has_ddi) sep \
>>>>   	func(has_fpga_dbg)
>>>>
>>>> -#define DEFINE_FLAG(name) u8 name:1
>>>> +#define DEFINE_FLAG(name) bool name:1
>>>>   #define SEP_SEMICOLON ;
>>>>
>>>>   struct intel_device_info {
>>>>
>>>
>>> The churn virus spreads? :)
>>>
>>> I tried that but it was negatively impacting the compiler. For some
>>> reason it increases .text by 2.5k here. Don't see anything obvious,
>>> would have to look at the code more closely to spot exactly why.
>>
>> Oh, that's not fun. bool:1 holds such promise for a clear explanation of
>> the most common form of bitfield.
>
> Really a bummer, especially since assigning any positive even number to
> unsigned int foo:1 will result in 0.

That is a pretty strong argument to go for this rather than make sure 
all places which set them are correct.

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko


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