drm/nouveau: Fix a crash at card takedown for NV40 and older cards

NV40 and older cards (pre NV50) reserve a vram bo for the vga memory at
card init. This bo is then freed at card shutdown.  The problem is that
the ttm bo vram manager was already freed. So a crash occurs when the
vga bo is freed. The fix is to free the vga bo prior to freeing the ttm
bo vram manager. There might be other solutions but this seemed the
simplest to me.

Signed-off-by: Jimmy Rentz <jb17bsome@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

2 files changed, 5 insertions, 2 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_mem.c b/drivers/gpu/drm/nouveau/nouveau_mem.c
index 5045f8b921d6..c3e953b08992 100644
--- a/drivers/gpu/drm/nouveau/nouveau_mem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_mem.c
@@ -152,8 +152,6 @@ nouveau_mem_vram_fini(struct drm_device *dev)
 {
         struct drm_nouveau_private *dev_priv = dev->dev_private;
 
-        nouveau_bo_ref(NULL, &dev_priv->vga_ram);
-
         ttm_bo_device_release(&dev_priv->ttm.bdev);
 
         nouveau_ttm_global_release(dev_priv);
diff --git a/drivers/gpu/drm/nouveau/nouveau_state.c b/drivers/gpu/drm/nouveau/nouveau_state.c
index a30adec5beaa..915fbce89595 100644
--- a/drivers/gpu/drm/nouveau/nouveau_state.c
+++ b/drivers/gpu/drm/nouveau/nouveau_state.c
@@ -768,6 +768,11 @@ static void nouveau_card_takedown(struct drm_device *dev)
         engine->mc.takedown(dev);
         engine->display.late_takedown(dev);
 
+        if (dev_priv->vga_ram) {
+                nouveau_bo_unpin(dev_priv->vga_ram);
+                nouveau_bo_ref(NULL, &dev_priv->vga_ram);
+        }
+
         mutex_lock(&dev->struct_mutex);
         ttm_bo_clean_mm(&dev_priv->ttm.bdev, TTM_PL_VRAM);
         ttm_bo_clean_mm(&dev_priv->ttm.bdev, TTM_PL_TT);