drm/nouveau: fix null pointer deref on pre-nv50 chipsets

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

1 files changed, 11 insertions, 5 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_object.c b/drivers/gpu/drm/nouveau/nouveau_object.c
index 542b451c81f1..fb57c1110d24 100644
--- a/drivers/gpu/drm/nouveau/nouveau_object.c
+++ b/drivers/gpu/drm/nouveau/nouveau_object.c
@@ -870,16 +870,22 @@ void
 nouveau_gpuobj_channel_takedown(struct nouveau_channel *chan)
 {
         struct drm_device *dev = chan->dev;
+        struct drm_nouveau_private *dev_priv = dev->dev_private;
         int i;
 
         NV_DEBUG(dev, "ch%d\n", chan->id);
 
-        for (i = 0; i < 2; i++) {
-                struct nv50_display_crtc *dispc = &nv50_display(dev)->crtc[i];
-                nouveau_bo_vma_del(dispc->sem.bo, &chan->dispc_vma[i]);
+        if (dev_priv->card_type >= NV_50) {
+                struct nv50_display *disp = nv50_display(dev);
+
+                for (i = 0; i < 2; i++) {
+                        struct nv50_display_crtc *dispc = &disp->crtc[i];
+                        nouveau_bo_vma_del(dispc->sem.bo, &chan->dispc_vma[i]);
+                }
+
+                nouveau_vm_ref(NULL, &chan->vm, chan->vm_pd);
+                nouveau_gpuobj_ref(NULL, &chan->vm_pd);
         }
-        nouveau_vm_ref(NULL, &chan->vm, chan->vm_pd);
-        nouveau_gpuobj_ref(NULL, &chan->vm_pd);
 
         if (drm_mm_initialized(&chan->ramin_heap))
                 drm_mm_takedown(&chan->ramin_heap);