drm/nve4/graph: do not crash if no power device present

Detect and workaround the absence of a power device so chips that do not
feature one (e.g. GK20A) can still use this driver.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/core/engine/graph/nve4.c b/drivers/gpu/drm/nouveau/core/engine/graph/nve4.c
index 1ba6666..fb9cb92 100644 (file)
--- a/drivers/gpu/drm/nouveau/core/engine/graph/nve4.c
+++ b/drivers/gpu/drm/nouveau/core/engine/graph/nve4.c
@@ -203,7 +203,8 @@ nve4_graph_init(struct nouveau_object *object)
        int gpc, tpc, rop;
        int ret, i;
 
-       ppwr->pgob(ppwr, false);
+       if (ppwr)
+               ppwr->pgob(ppwr, false);
 
        ret = nouveau_graph_init(&priv->base);
        if (ret)