drm/ttm: Fixed a read/write lock imbalance

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.

Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_lock.c b/drivers/gpu/drm/ttm/ttm_lock.c
index 6a954544727f..f154fb1929bd 100644
--- 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;
 }