gpu: nvgpu: Enable clocks only if defined

Enable clocks only if they are defined. This prevents panic in cases
where clock does not need to be enabled explicitly.

Bug 1567274

Change-Id: I7113c6d874b61acc2646effda9c02d3d1817c531
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.c b/drivers/gpu/nvgpu/gk20a/gk20a.c
index c91a316a..85864bcd 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.c
@@ -1146,7 +1146,9 @@ static int gk20a_pm_enable_clk(struct device *dev)
                 return -EINVAL;
 
         for (index = 0; index < platform->num_clks; index++) {
-                int err = clk_prepare_enable(platform->clk[index]);
+                int err = 0;
+                if (platform->clk[index])
+                        clk_prepare_enable(platform->clk[index]);
                 if (err)
                         return -EINVAL;
         }
@@ -1163,8 +1165,10 @@ static int gk20a_pm_disable_clk(struct device *dev)
         if (!platform)
                 return -EINVAL;
 
-        for (index = 0; index < platform->num_clks; index++)
-                clk_disable_unprepare(platform->clk[index]);
+        for (index = 0; index < platform->num_clks; index++) {
+                if (platform->clk[index])
+                        clk_disable_unprepare(platform->clk[index]);
+        }
 
         return 0;
 }