1 files changed, 11 insertions, 5 deletions

diff --git a/drivers/gpu/nvgpu/lpwr/lpwr.c b/drivers/gpu/nvgpu/lpwr/lpwr.c
index 4f8d2eec..e3483cca 100644
--- a/drivers/gpu/nvgpu/lpwr/lpwr.c
+++ b/drivers/gpu/nvgpu/lpwr/lpwr.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2016-2017, NVIDIA CORPORATION.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -362,8 +362,11 @@ int nvgpu_lpwr_enable_pg(struct gk20a *g, bool pstate_lock)
         is_mscg_supported = nvgpu_lpwr_is_mscg_supported(g,
                         present_pstate);
         if (is_mscg_supported && g->mscg_enabled) {
-                if (!pmu->mscg_stat)
-                        pmu->mscg_stat = PMU_MSCG_ENABLED;
+                if (!ACCESS_ONCE(pmu->mscg_stat)) {
+                        WRITE_ONCE(pmu->mscg_stat, PMU_MSCG_ENABLED);
+                        /* make status visible */
+                        smp_mb();
+                }
         }
 
         is_rppg_supported = nvgpu_lpwr_is_rppg_supported(g,
@@ -409,8 +412,11 @@ int nvgpu_lpwr_disable_pg(struct gk20a *g, bool pstate_lock)
         is_mscg_supported = nvgpu_lpwr_is_mscg_supported(g,
                         present_pstate);
         if (is_mscg_supported && g->mscg_enabled) {
-                if (pmu->mscg_stat)
-                        pmu->mscg_stat = PMU_MSCG_DISABLED;
+                if (ACCESS_ONCE(pmu->mscg_stat)) {
+                        WRITE_ONCE(pmu->mscg_stat, PMU_MSCG_DISABLED);
+                        /* make status visible */
+                        smp_mb();
+                }
         }
 
 exit_unlock: