[PATCH AUTOSEL for 4.15 055/102] drm/amdgpu:fix random missing of FLR NOTIFY

[Sasha Levin]

From: Monk Liu <Monk.Liu@xxxxxxx>

[ Upstream commit 34a4d2bf06b3ab92024b8e26d6049411369d1f1a ]

Signed-off-by: Monk Liu <Monk.Liu@xxxxxxx>
Acked-by: Christian KÃnig <christian.koenig@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/amd/amdgpu/mxgpu_ai.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/mxgpu_ai.c b/drivers/gpu/drm/amd/amdgpu/mxgpu_ai.c
index b4906d2f30d3..0031f8f34db5 100644
--- a/drivers/gpu/drm/amd/amdgpu/mxgpu_ai.c
+++ b/drivers/gpu/drm/amd/amdgpu/mxgpu_ai.c
@@ -282,9 +282,17 @@ static int xgpu_ai_mailbox_rcv_irq(struct amdgpu_device *adev,
 		/* see what event we get */
 		r = xgpu_ai_mailbox_rcv_msg(adev, IDH_FLR_NOTIFICATION);
 
-		/* only handle FLR_NOTIFY now */
-		if (!r)
-			schedule_work(&adev->virt.flr_work);
+		/* sometimes the interrupt is delayed to inject to VM, so under such case
+		 * the IDH_FLR_NOTIFICATION is overwritten by VF FLR from GIM side, thus
+		 * above recieve message could be failed, we should schedule the flr_work
+		 * anyway
+		 */
+		if (r) {
+			DRM_ERROR("FLR_NOTIFICATION is missed\n");
+			xgpu_ai_mailbox_send_ack(adev);
+		}
+
+		schedule_work(&adev->virt.flr_work);
 	}
 
 	return 0;
-- 
2.14.1