drm/ttm: Fixed a read/write lock imbalance

commit 025af189fb44250206dd8a32fa4a682392af3301 upstream.

In ttm_write_lock(), the uninterruptible path should call
__ttm_write_lock() not __ttm_read_lock().  This fixes a vmwgfx hang
on F23 start up.

syeh: Extracted this from one of Thomas' internal patches.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/gpu/drm/ttm/ttm_lock.c b/drivers/gpu/drm/ttm/ttm_lock.c
index 075daf44bce406516b2b6e1f3b2ce905b2cd97f2..9934b4d2350b0cba2d0e6c69fdff7229a79a2218 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_lock.c
+++ b/drivers/gpu/drm/ttm/ttm_lock.c
@@ -180,7 +180,7 @@ int ttm_write_lock(struct ttm_lock *lock, bool interruptible)
                        spin_unlock(&lock->lock);
                }
        } else
-               wait_event(lock->queue, __ttm_read_lock(lock));
+               wait_event(lock->queue, __ttm_write_lock(lock));
 
        return ret;
 }