drm/nouveau/pm: fix oops if chipset has no pm support at all

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_pm.c b/drivers/gpu/drm/nouveau/nouveau_pm.c
index dcc16927716f..34d591b7d4ef 100644
--- a/drivers/gpu/drm/nouveau/nouveau_pm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_pm.c
@@ -284,9 +284,11 @@ nouveau_pm_perflvl_get(struct drm_device *dev, struct nouveau_pm_level *perflvl)
 
         memset(perflvl, 0, sizeof(*perflvl));
 
-        ret = pm->clocks_get(dev, perflvl);
-        if (ret)
-                return ret;
+        if (pm->clocks_get) {
+                ret = pm->clocks_get(dev, perflvl);
+                if (ret)
+                        return ret;
+        }
 
         if (pm->voltage.supported && pm->voltage_get) {
                 ret = pm->voltage_get(dev);