From 352c83fb39cae3eff95a8e1ed23006291abb6196 Mon Sep 17 00:00:00 2001
From: Rob Clark <robdclark@chromium.org>
Date: Mon, 17 Aug 2020 09:23:09 -0700
Subject: drm/msm/gpu: make ringbuffer readonly
Git-commit: 352c83fb39cae3eff95a8e1ed23006291abb6196
Patch-mainline: v5.9-rc3
References: bsc#1112178

The GPU has no business writing into the ringbuffer, let's make it
readonly to the GPU.

Fixes: 7198e6b03155 ("drm/msm: add a3xx gpu support")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/msm/msm_ringbuffer.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/msm/msm_ringbuffer.c
+++ b/drivers/gpu/drm/msm/msm_ringbuffer.c
@@ -38,7 +38,7 @@ struct msm_ringbuffer *msm_ringbuffer_ne
 	ring->id = id;
 	/* Pass NULL for the iova pointer - we will map it later */
 	ring->start = msm_gem_kernel_new(gpu->dev, MSM_GPU_RINGBUFFER_SZ,
-		MSM_BO_WC, gpu->aspace, &ring->bo, NULL);
+		MSM_BO_WC | MSM_BO_GPU_READONLY, gpu->aspace, &ring->bo, NULL);
 
 	if (IS_ERR(ring->start)) {
 		ret = PTR_ERR(ring->start);