On 11/6/25 17:37, Kuehling, Felix wrote: > > On 2025-11-06 08:43, Christian König wrote: >> 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. > > I guess we could use dma_fence_is_signaled_locked instead. That said, it only > tries to take the lock (in dma_fence_signal) if fence->ops->signal is set, > which isn't the case for these fences. That's why this has never caused a > problem up till now.
But when fence->ops->signal isn't set then why are we calling this? Regards, Christian. > > Regards, > Felix > > >> >> Thanks, >> Christian. >> >>> >>> P. >>> >>>> Signed-off-by: Christian König <[email protected]> >>>> --- >>>> 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;
