From: "Xiangliang.Yu" <Xiangliang.Yu@amd.com>
Date: Fri, 10 Nov 2017 14:23:38 +0800
Subject: drm/amdgpu/gfx8: Fix compute ring failure after resetting
Git-commit: 75737cb4eb78c7f185e4700b4aa20cf7a3381aca
Patch-mainline: v4.16-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Do ring clear before ring test, otherwise compute ring test will
fail after gpu resetting. Still can't find the root cause, just
workaround it.

Signed-off-by: Xiangliang.Yu <Xiangliang.Yu@amd.com>
Acked-by: Monk Liu <Monk.Liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
@@ -4877,9 +4877,6 @@ static int gfx_v8_0_kcq_init_queue(struc
 		/* reset MQD to a clean status */
 		if (adev->gfx.mec.mqd_backup[mqd_idx])
 			memcpy(mqd, adev->gfx.mec.mqd_backup[mqd_idx], sizeof(struct vi_mqd_allocation));
-		/* reset ring buffer */
-		ring->wptr = 0;
-		amdgpu_ring_clear_ring(ring);
 	} else {
 		amdgpu_ring_clear_ring(ring);
 	}
@@ -4954,6 +4951,13 @@ static int gfx_v8_0_kiq_resume(struct am
 	/* Test KCQs */
 	for (i = 0; i < adev->gfx.num_compute_rings; i++) {
 		ring = &adev->gfx.compute_ring[i];
+		if (adev->in_gpu_reset) {
+			/* move reset ring buffer to here to workaround
+			 * compute ring test failed
+			 */
+			ring->wptr = 0;
+			amdgpu_ring_clear_ring(ring);
+		}
 		ring->ready = true;
 		r = amdgpu_ring_test_ring(ring);
 		if (r)