[PATCH] drm/amdgpu: Fix display freezing issue when resizing apps

[Arvind Yadav]

The display is freezing because the amdgpu_userq_wait_ioctl()
is waiting for a non-user queue fence(specifically, the PT update fence).

RootCause:
The resume_work is initiated by both amdgpu_userq_suspend and
amdgpu_userqueue_ensure_ev_fence at same time. The amdgpu_userq_suspend
signals a dma-fence and subsequently triggers the resume_work, which is
intended to replace the existing fence by creating new dma-fence. However,
following this, the amdgpu_userqueue_ensure_ev_fence schedules another
resume_work that generates a new dma-fence, thereby replacing the one
created by amdgpu_userq_suspend. Consequently, the original fence will
never be signaled.

Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: Christian König <christian.koenig at amd.com>
Cc: Shashank Sharma <shashank.sharma at amd.com>
Cc: Sunil Khatri <sunil.khatri at amd.com>
Signed-off-by: Arvind Yadav <arvind.yadav at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c
index 167951aee502..0075469550b0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c
@@ -52,6 +52,9 @@ amdgpu_eviction_fence_replace_fence(struct amdgpu_eviction_fence_mgr *evf_mgr,
 	unsigned long index;
 	int ret;
 
+	if (evf_mgr->ev_fence &&
+	    !dma_fence_is_signaled(&evf_mgr->ev_fence->base))
+		return 0;
 	/*
 	 * Steps to replace eviction fence:
 	 * * lock all objects in exec (caller)
-- 
2.34.1