[PATCH] drm/amdgpu: Fix mc_umc_status used uninitialized warning

[Leo Li]

On 2022-09-28 10:53, Hamza Mahfooz wrote:
> On 2022-09-28 10:49, sunpeng.li at amd.com wrote:
>> From: Leo Li <sunpeng.li at amd.com>
>>
>> On ChromeOS clang build, the following warning is seen:
>>
>> /mnt/host/source/src/third_party/kernel/v5.15/drivers/gpu/drm/amd/amdgpu/umc_v6_7.c:463:6: error: variable 'mc_umc_status' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
>>          if (mca_addr == UMC_INVALID_ADDR) {
>>              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> /mnt/host/source/src/third_party/kernel/v5.15/drivers/gpu/drm/amd/amdgpu/umc_v6_7.c:485:21: note: uninitialized use occurs here
>>          if ((REG_GET_FIELD(mc_umc_status, 
>> MCA_UMC_UMC0_MCUMC_STATUST0, Val) == 1 &&
>>                             ^~~~~~~~~~~~~
>> /mnt/host/source/src/third_party/kernel/v5.15/drivers/gpu/drm/amd/amdgpu/../amdgpu/amdgpu.h:1208:5: note: expanded from macro 'REG_GET_FIELD'
>>          (((value) & REG_FIELD_MASK(reg, field)) >> 
>> REG_FIELD_SHIFT(reg, field))
>>             ^~~~~
>> /mnt/host/source/src/third_party/kernel/v5.15/drivers/gpu/drm/amd/amdgpu/umc_v6_7.c:463:2: note: remove the 'if' if its condition is always true
>>          if (mca_addr == UMC_INVALID_ADDR) {
>>          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> /mnt/host/source/src/third_party/kernel/v5.15/drivers/gpu/drm/amd/amdgpu/umc_v6_7.c:460:24: note: initialize the variable 'mc_umc_status' to silence this warning
>>          uint64_t mc_umc_status, mc_umc_addrt0;
>>                                ^
>>                                 = 0
>> 1 error generated.
>> make[5]: *** 
>> [/mnt/host/source/src/third_party/kernel/v5.15/scripts/Makefile.build:289: drivers/gpu/drm/amd/amdgpu/umc_v6_7.o] Error 1
>>
>> Fix by initializing mc_umc_status = 0.
>>
>> Fixes: d8e19e32945e ("drm/amdgpu: support to convert dedicated umc mca 
>> address")
>> Signed-off-by: Leo Li <sunpeng.li at amd.com>
> 
> Reviewed-by: Hamza Mahfooz <hamza.mahfooz at amd.com>

Thanks! Will merge shortly.
Leo