3 files changed, 14 insertions, 4 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/clk_gk20a.h b/drivers/gpu/nvgpu/gk20a/clk_gk20a.h
index 03aa6ab7..b8ec9420 100644
--- a/drivers/gpu/nvgpu/gk20a/clk_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/clk_gk20a.h
@@ -95,6 +95,7 @@ struct clk_gk20a {
         struct gk20a *g;
 #if defined(CONFIG_COMMON_CLK)
         struct clk *tegra_clk;
+        struct clk *tegra_clk_parent;
         struct clk_hw hw;
 #endif
         struct pll gpc_pll;
diff --git a/drivers/gpu/nvgpu/os/linux/clk.c b/drivers/gpu/nvgpu/os/linux/clk.c
index 6575a037..471f2aef 100644
--- a/drivers/gpu/nvgpu/os/linux/clk.c
+++ b/drivers/gpu/nvgpu/os/linux/clk.c
@@ -90,7 +90,7 @@ static unsigned long nvgpu_linux_get_fmax_at_vmin_safe(struct gk20a *g)
          */
         if (g->clk.tegra_clk)
                 return tegra_dvfs_get_fmax_at_vmin_safe_t(
-                        clk_get_parent(g->clk.tegra_clk));
+                        g->clk.tegra_clk_parent);
 
         if (platform->maxmin_clk_id)
                 return tegra_bpmp_dvfs_get_fmax_at_vmin(
@@ -116,7 +116,7 @@ static int nvgpu_linux_predict_mv_at_hz_cur_tfloor(struct clk_gk20a *clk,
         unsigned long rate)
 {
         return tegra_dvfs_predict_mv_at_hz_cur_tfloor(
-                                clk_get_parent(clk->tegra_clk), rate);
+                                clk->tegra_clk_parent, rate);
 }
 
 static unsigned long nvgpu_linux_get_maxrate(struct gk20a *g, u32 api_domain)
@@ -125,7 +125,7 @@ static unsigned long nvgpu_linux_get_maxrate(struct gk20a *g, u32 api_domain)
 
         switch (api_domain) {
         case CTRL_CLK_DOMAIN_GPCCLK:
-                ret = tegra_dvfs_get_maxrate(clk_get_parent(g->clk.tegra_clk));
+                ret = tegra_dvfs_get_maxrate(g->clk.tegra_clk_parent);
                 break;
         default:
                 nvgpu_err(g, "unknown clock: %u", api_domain);
diff --git a/drivers/gpu/nvgpu/os/linux/platform_gk20a_tegra.c b/drivers/gpu/nvgpu/os/linux/platform_gk20a_tegra.c
index 6a453096..0977e63a 100644
--- a/drivers/gpu/nvgpu/os/linux/platform_gk20a_tegra.c
+++ b/drivers/gpu/nvgpu/os/linux/platform_gk20a_tegra.c
@@ -649,7 +649,7 @@ int gk20a_tegra_init_secure_alloc(struct gk20a_platform *platform)
 static struct clk *gk20a_clk_get(struct gk20a *g)
 {
         if (!g->clk.tegra_clk) {
-                struct clk *clk;
+                struct clk *clk, *clk_parent;
                 char clk_dev_id[32];
                 struct device *dev = dev_from_gk20a(g);
 
@@ -661,7 +661,16 @@ static struct clk *gk20a_clk_get(struct gk20a *g)
                                   clk_dev_id);
                         return NULL;
                 }
+
+                clk_parent = clk_get_parent(clk);
+                if (IS_ERR_OR_NULL(clk_parent)) {
+                        nvgpu_err(g, "fail to get tegra gpu clk parent%s/gpu\n",
+                                  clk_dev_id);
+                        return NULL;
+                }
+
                 g->clk.tegra_clk = clk;
+                g->clk.tegra_clk_parent = clk_parent;
         }
 
         return g->clk.tegra_clk;