Re: [PATCH 11/20] drm/amdgpu: fix KFD eviction fence enable_signaling path

["Christian König" <christian.koenig@amd.com>]

On 11/4/25 17:28, Philipp Stanner wrote:
> On Fri, 2025-10-31 at 14:16 +0100, Christian König wrote:
>> Calling dma_fence_is_signaled() here is illegal!
> 
> The series was sent as a v2. But is this still an RFC?

I think when Matthew came up with the XE patches we pretty much agreed that this is the way to go.

> 
> If not, more detailed commit messages are a desirable thing.

Good point, how about:

The enable_signaling callback is called with the same irqsave spinlock held than dma_fence_is_signaled() tries to grab. That will 100% reliable deadlock if that happens.

Thanks,
Christian.

> 
> 
> P.
> 
>>
>> Signed-off-by: Christian König <christian.koenig@amd.com>
>> ---
>>  drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c | 6 ------
>>  1 file changed, 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c
>> index 1ef758ac5076..09c919f72b6c 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c
>> @@ -120,12 +120,6 @@ static bool amdkfd_fence_enable_signaling(struct
>> dma_fence *f)
>>  {
>>  	struct amdgpu_amdkfd_fence *fence =
>> to_amdgpu_amdkfd_fence(f);
>>  
>> -	if (!fence)
>> -		return false;
>> -
>> -	if (dma_fence_is_signaled(f))
>> -		return true;
>> -
>>  	if (!fence->svm_bo) {
>>  		if
>> (!kgd2kfd_schedule_evict_and_restore_process(fence->mm, f))
>>  			return true;
>