[PATCH v2 2/2] drm/amdgpu: Process fences on IH overflow

[Friedrich Vock]

If the IH ring buffer overflows, it's possible that fence signal events
were lost. Check each ring for progress to prevent job timeouts/GPU
hangs due to the fences staying unsignaled despite the work being done.

Cc: Joshua Ashton <joshua at froggi.es>
Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: Christian König <christian.koenig at amd.com>
Cc: stable at vger.kernel.org

Signed-off-by: Friedrich Vock <friedrich.vock at gmx.de>
---
v2: Set ih->overflow to false after processing fences

 drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
index f3b0aaf3ebc6..4e061f7741d8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
@@ -209,6 +209,7 @@ int amdgpu_ih_process(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih)
 {
 	unsigned int count;
 	u32 wptr;
+	int i;

 	if (!ih->enabled || adev->shutdown)
 		return IRQ_NONE;
@@ -227,6 +228,21 @@ int amdgpu_ih_process(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih)
 		ih->rptr &= ih->ptr_mask;
 	}

+	/* If the ring buffer overflowed, we might have lost some fence
+	 * signal interrupts. Check if there was any activity so the signal
+	 * doesn't get lost.
+	 */
+	if (ih->overflow) {
+		for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
+			struct amdgpu_ring *ring = adev->rings[i];
+
+			if (!ring || !ring->fence_drv.initialized)
+				continue;
+			amdgpu_fence_process(ring);
+		}
+		ih->overflow = false;
+	}
+
 	amdgpu_ih_set_rptr(adev, ih);
 	wake_up_all(&ih->wait_process);

--
2.43.0