Here's setting software signaling bit for the stub fence
which is always signaled. If this fence signaling bit is
not set then the AMD GPU scheduler will cause a GPU reset
due to a GPU scheduler cleanup activity timeout.

Signed-off-by: Arvind Yadav <Arvind.Yadav@amd.com>
---

Changes in v1 :
1- Addressing Christian's comment to remove unnecessary callback.
2- Replacing CONFIG_DEBUG_WW_MUTEX_SLOWPATH instead of CONFIG_DEBUG_FS.
3- The version of this patch is also changed and previously
it was [PATCH 3/4]

Changes in v2 : 
1 - perviously using  __dma_fence_enable_signaling() for enable
signaling.
2 - #ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH  removed

---
 drivers/dma-buf/dma-fence.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index 64c99739ad23..bead1a6e9f59 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -136,6 +136,10 @@ struct dma_fence *dma_fence_get_stub(void)
 			       &dma_fence_stub_ops,
 			       &dma_fence_stub_lock,
 			       0, 0);
+
+		set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
+			&dma_fence_stub.flags);
+
 		dma_fence_signal_locked(&dma_fence_stub);
 	}
 	spin_unlock(&dma_fence_stub_lock);
-- 
2.25.1

Am 09.09.22 um 19:08 schrieb Arvind Yadav:
> Here's setting software signaling bit for the stub fence
> which is always signaled. If this fence signaling bit is
> not set then the AMD GPU scheduler will cause a GPU reset
> due to a GPU scheduler cleanup activity timeout.
>
> Signed-off-by: Arvind Yadav <Arvind.Yadav@amd.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>
> Changes in v1 :
> 1- Addressing Christian's comment to remove unnecessary callback.
> 2- Replacing CONFIG_DEBUG_WW_MUTEX_SLOWPATH instead of CONFIG_DEBUG_FS.
> 3- The version of this patch is also changed and previously
> it was [PATCH 3/4]
>
> Changes in v2 :
> 1 - perviously using  __dma_fence_enable_signaling() for enable
> signaling.
> 2 - #ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH  removed
>
> ---
>   drivers/dma-buf/dma-fence.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
> index 64c99739ad23..bead1a6e9f59 100644
> --- a/drivers/dma-buf/dma-fence.c
> +++ b/drivers/dma-buf/dma-fence.c
> @@ -136,6 +136,10 @@ struct dma_fence *dma_fence_get_stub(void)
>   			       &dma_fence_stub_ops,
>   			       &dma_fence_stub_lock,
>   			       0, 0);
> +
> +		set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
> +			&dma_fence_stub.flags);
> +
>   		dma_fence_signal_locked(&dma_fence_stub);
>   	}
>   	spin_unlock(&dma_fence_stub_lock);