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From f228af11dfa1d1616bc67f3a4119ab77c36181f1 Mon Sep 17 00:00:00 2001
From: Rob Clark <robdclark@chromium.org>
Date: Wed, 12 Aug 2020 17:03:09 -0700
Subject: [PATCH] drm/msm/adreno: fix updating ring fence
Git-commit: f228af11dfa1d1616bc67f3a4119ab77c36181f1
Patch-mainline: v5.9-rc3
References: git-fixes

We need to set it to the most recent completed fence, not the most
recent submitted.  Otherwise we have races where we think we can retire
submits that the GPU is not finished with, if the GPU doesn't manage to
overwrite the seqno before we look at it.

This can show up with hang recovery if one of the submits after the
crashing submit also hangs after it is replayed.

Fixes: f97decac5f4c ("drm/msm: Support multiple ringbuffers")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/msm/adreno/adreno_gpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index e23641a5ec84..d2dbb6968cba 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -396,7 +396,7 @@ int adreno_hw_init(struct msm_gpu *gpu)
 		ring->next = ring->start;
 
 		/* reset completed fence seqno: */
-		ring->memptrs->fence = ring->seqno;
+		ring->memptrs->fence = ring->fctx->completed_fence;
 		ring->memptrs->rptr = 0;
 	}
 
-- 
2.16.4