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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Jordan Crouse <jcrouse@codeaurora.org>,
        Rob Clark <robdclark@chromium.org>
Subject: [PATCH 4.19 62/78] drm/msm: Disable preemption on all 5xx targets
Date:   Tue, 15 Sep 2020 16:13:27 +0200
Message-Id: <20200915140636.681025431@linuxfoundation.org>
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From: Jordan Crouse <jcrouse@codeaurora.org>

commit 7b3f3948c8b7053d771acc9f79810cc410f5e2e0 upstream.

Temporarily disable preemption on a5xx targets pending some improvements
to protect the RPTR shadow from being corrupted.

Cc: stable@vger.kernel.org
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/msm/adreno/a5xx_gpu.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
@@ -1518,7 +1518,8 @@ struct msm_gpu *a5xx_gpu_init(struct drm
 
 	check_speed_bin(&pdev->dev);
 
-	ret = adreno_gpu_init(dev, pdev, adreno_gpu, &funcs, 4);
+	/* Restricting nr_rings to 1 to temporarily disable preemption */
+	ret = adreno_gpu_init(dev, pdev, adreno_gpu, &funcs, 1);
 	if (ret) {
 		a5xx_destroy(&(a5xx_gpu->base.base));
 		return ERR_PTR(ret);