drm/nouveau: fix locking issues in page flipping paths

b580c9e2b7ba5030a795aa2fb73b796523d65a78 introduced additional problems
while trying to solve issues that became apparent while porting to the
new reservation stuff.

The major problem was that the the previously mentioned patch took the
client mutex earlier than previously, but the pinning of new_bo can
can potentially cause a buffer move, which would result in attempting to
acquire the same mutex again.

This commit attempts to fix that "fix".

Thanks to Maarten for the tips on keeping lockdep happy and cooking :)

Reported-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Acked-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>

1 files changed, 0 insertions, 3 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
index 218a4b522fe5..4eca52b8d573 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -284,8 +284,6 @@ static int nouveau_drm_probe(struct pci_dev *pdev,
         return 0;
 }
 
-static struct lock_class_key drm_client_lock_class_key;
-
 static int
 nouveau_drm_load(struct drm_device *dev, unsigned long flags)
 {
@@ -297,7 +295,6 @@ nouveau_drm_load(struct drm_device *dev, unsigned long flags)
         ret = nouveau_cli_create(pdev, "DRM", sizeof(*drm), (void**)&drm);
         if (ret)
                 return ret;
-        lockdep_set_class(&drm->client.mutex, &drm_client_lock_class_key);
 
         dev->dev_private = drm;
         drm->dev = dev;