drm/amdgpu: Deactivate SW interrupt fallback in amdgpu_fence_process v2

Deactivate SW interrupt fallback when all emited fences are completed.
Also switch interrupt SW fallback message from INFO to WARN.

v2: shorten the warning message a bit and only re-activate the timer during
processing if it was already activated before. (Christian)
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Suggested-by: Christian Konig <Christian.Koenig@amd.com>
Reviewed-and-Tested-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c

@@ -229,7 +229,8 @@ void amdgpu_fence_process(struct amdgpu_ring *ring)
 
 	} while (atomic_cmpxchg(&drv->last_seq, last_seq, seq) != last_seq);
 
-	if (seq != ring->fence_drv.sync_seq)
+	if (del_timer(&ring->fence_drv.fallback_timer) &&
+	    seq != ring->fence_drv.sync_seq)
 		amdgpu_fence_schedule_fallback(ring);
 
 	if (unlikely(seq == last_seq))
@@ -274,7 +275,7 @@ static void amdgpu_fence_fallback(struct timer_list *t)
 	struct amdgpu_ring *ring = from_timer(ring, t,
 					      fence_drv.fallback_timer);
 
-	DRM_INFO("Fallback to SW interrupt on ring %s due to HW interrupt time out", ring->name);
+	DRM_WARN("Fence fallback timer expired on ring %s\n", ring->name);
 	amdgpu_fence_process(ring);
 }