[PATCH] drm/amdgpu: Fix the iounmap error of rmmio

[Ma, Jun]

Hi Christian,

On 3/15/2024 3:16 PM, Christian König wrote:
> Am 15.03.24 um 06:17 schrieb Ma Jun:
>> Setting the rmmio pointer to NULL to fix the following
>> iounmap error and calltrace.
>> iounmap: bad address 00000000d0b3631f
>>
>> Fixes: 923f7a82d2e1 ("drm/amd/amdgpu: Fix potential ioremap() memory leaks in amdgpu_device_init()")
>> Signed-off-by: Ma Jun <Jun.Ma2 at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 7 +++++--
>>   1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> index 39dd76e57154..d65a6aabefbb 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> @@ -4383,6 +4383,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
>>   
>>   unmap_memory:
>>   	iounmap(adev->rmmio);
>> +	adev->rmmio = NULL;
> 
> Well that doesn't looks correct to me. You seem to be working around 
> broken initialisation code here.

I got this error when I tried to rescan the gpu device after removing it.

Regards,
Ma Jun
> 
>>   	return r;
>>   }
>>   
>> @@ -4514,9 +4515,11 @@ void amdgpu_device_fini_sw(struct amdgpu_device *adev)
>>   #endif
>>   
>>   	if (drm_dev_enter(adev_to_drm(adev), &idx)) {
> 
> Ok, well that alone doesn't look correct to me. The MMIO regions needs 
> to be unmapped independent if the driver is disconnected or not.
> 
>> +		if (adev->rmmio) {
> 
> That looks just like a hack to me.
> 
> Regards,
> Christian.
> 
>> +			iounmap(adev->rmmio);
>> +			adev->rmmio = NULL;
>> +		}
>>   
>> -		iounmap(adev->rmmio);
>> -		adev->rmmio = NULL;
>>   		amdgpu_doorbell_fini(adev);
>>   		drm_dev_exit(idx);
>>   	}
>