[PATCH] drm/xe: Fix warning on impossible condition

[Lucas De Marchi]

On Wed, Jan 03, 2024 at 09:07:36AM -0700, Nathan Chancellor wrote:
>On Mon, Dec 18, 2023 at 08:33:01AM -0800, Lucas De Marchi wrote:
>> Having a different value for op is not possible: this is already kept
>> out of user-visible warning by the check in xe_wait_user_fence_ioctl()
>> if op > MAX_OP. The warning is useful as if this switch() is not update
>> when a new op is added, it should be triggered.
>>
>> Fix warning as reported by 0-DAY CI Kernel:
>>
>> 	drivers/gpu/drm/xe/xe_wait_user_fence.c:46:2: warning: variable 'passed' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
>>
>> Closes: https://lore.kernel.org/oe-kbuild-all/202312170357.KPSinwPs-lkp@intel.com/
>> Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
>> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
>
>Reviewed-by: Nathan Chancellor <nathan at kernel.org>
>
>I am now seeing this warning in -next, can this be applied as a fix so
>that our builds are not broken?

pull request including this fix was created last week:
https://lore.kernel.org/all/ZYsbDPBLUiqDevLt@intel.com/

Lucas De Marchi

>
>> ---
>>  drivers/gpu/drm/xe/xe_wait_user_fence.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_wait_user_fence.c b/drivers/gpu/drm/xe/xe_wait_user_fence.c
>> index b0a7896f7fcb..a75eeba7bfe5 100644
>> --- a/drivers/gpu/drm/xe/xe_wait_user_fence.c
>> +++ b/drivers/gpu/drm/xe/xe_wait_user_fence.c
>> @@ -46,6 +46,7 @@ static int do_compare(u64 addr, u64 value, u64 mask, u16 op)
>>  		break;
>>  	default:
>>  		XE_WARN_ON("Not possible");
>> +		return -EINVAL;
>>  	}
>>
>>  	return passed ? 0 : 1;
>> --
>> 2.40.1
>>