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.

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;

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