gpu: nvgpu: re-enable elpg after golden img init

Typically, the PMU init thread will finish up long
before the golden context image has been initialized,
which means that ELPG hasn't truly been enabled at that
point.

Create a new function, nvgpu_pmu_reenable_pg(), which
checks if elpg had been enabled (non-zero refcnt), and
if so, disables then re-enables it.

Call this function from gk20a_alloc_obj_ctx() after
the golden context image has been initialized to ensure
that elpg is truly enabled.

Manually ported from dev-main

Bug 200543218

Change-Id: I0e7c4f64434c5e356829581950edce61cc88882a
Signed-off-by: Peter Daifuku <pdaifuku@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/2245768
(cherry picked from commit 077b6712b5a40340ece818416002ac8431dc4138)
Reviewed-on: https://git-master.nvidia.com/r/2250091
GVS: Gerrit_Virtual_Submit
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>
Reviewed-by: Bibek Basu <bbasu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 31 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/common/pmu/pmu_pg.c b/drivers/gpu/nvgpu/common/pmu/pmu_pg.c
index 3d46298d..941cee75 100644
--- a/drivers/gpu/nvgpu/common/pmu/pmu_pg.c
+++ b/drivers/gpu/nvgpu/common/pmu/pmu_pg.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2018, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2016-2019, NVIDIA CORPORATION.  All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -359,6 +359,36 @@ exit_unlock:
         return ret;
 }
 
+int nvgpu_pmu_reenable_elpg(struct gk20a *g)
+{
+        struct nvgpu_pmu *pmu = &g->pmu;
+        int ret = 0;
+
+        nvgpu_log_fn(g, " ");
+
+        if (!g->support_pmu) {
+                return ret;
+        }
+
+        /* If pmu enabled, re-enable by first disabling, then
+         * enabling
+         */
+        if (pmu->elpg_refcnt != 0) {
+                ret = nvgpu_pmu_disable_elpg(g);
+                if (ret != 0) {
+                        nvgpu_err(g, "failed disabling elpg");
+                        goto exit;
+                }
+                ret = nvgpu_pmu_enable_elpg(g);
+                if (ret != 0) {
+                        nvgpu_err(g, "failed enabling elpg");
+                        goto exit;
+                }
+        }
+exit:
+        return ret;
+}
+
 /* PG init */
 static void pmu_handle_pg_stat_msg(struct gk20a *g, struct pmu_msg *msg,
                         void *param, u32 handle, u32 status)