drm/nv50-nvc0: make sure vma is definitely unmapped when destroying bo

Somehow fixes a misrendering + hang at GDM startup on my NVA8...

My first guess would have been stale TLB entries laying around that a new
bo then accidentally inherits.  That doesn't make a great deal of sense
however, as when we mapped the pages for the new bo the TLBs would've
gotten flushed anyway.

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

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index d38a4d9f9b0b..a52184007f5f 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -49,7 +49,10 @@ nouveau_bo_del_ttm(struct ttm_buffer_object *bo)
                 DRM_ERROR("bo %p still attached to GEM object\n", bo);
 
         nv10_mem_put_tile_region(dev, nvbo->tile, NULL);
-        nouveau_vm_put(&nvbo->vma);
+        if (nvbo->vma.node) {
+                nouveau_vm_unmap(&nvbo->vma);
+                nouveau_vm_put(&nvbo->vma);
+        }
         kfree(nvbo);
 }