[PATCH 1/1] drm/amdgpu: return early on error while setting bar0 memtype

[Das, Nirmoy]

On 11/2/2021 9:00 AM, Lazar, Lijo wrote:
>
>
> On 10/29/2021 8:39 PM, Nirmoy Das wrote:
>> We set WC memtype for aper_base but don't check return value
>> of arch_io_reserve_memtype_wc(). Be more defensive and return
>> early on error.
>>
>> Signed-off-by: Nirmoy Das <nirmoy.das at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 7 ++++++-
>>   1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> index 073ba2af0b9c..6b25982a9077 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> @@ -1032,9 +1032,14 @@ int amdgpu_bo_init(struct amdgpu_device *adev)
>>       /* On A+A platform, VRAM can be mapped as WB */
>>       if (!adev->gmc.xgmi.connected_to_cpu) {
>>           /* reserve PAT memory space to WC for VRAM */
>> -        arch_io_reserve_memtype_wc(adev->gmc.aper_base,
>> +        int r = arch_io_reserve_memtype_wc(adev->gmc.aper_base,
>>                   adev->gmc.aper_size);
>
> BTW, isn't it more appropriate to use visible vram size? There are 
> cases where pci resize rounds aperture to the next higher size > size 
> of actual VRAM.


Good point, I will update this one and send again.


Regards,

Nirmoy


>
> Thanks,
> Lijo
>>   +        if (r) {
>> +            DRM_ERROR("Unable to set WC memtype for the aperture 
>> base\n");
>> +            return r;
>> +        }
>> +
>>           /* Add an MTRR for the VRAM */
>>           adev->gmc.vram_mtrr = arch_phys_wc_add(adev->gmc.aper_base,
>>                   adev->gmc.aper_size);
>>