i915: fix lock imbalance on error path...

While investigating Intel i5 Arrandale GPU lockups with -rc4, I
noticed a lock imbalance.

Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index d40f62d36453..c072b212979c 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -370,6 +370,7 @@ int i965_reset(struct drm_device *dev, u8 flags)
                 }
         } else {
                 DRM_ERROR("Error occurred. Don't know how to reset this chip.\n");
+                mutex_unlock(&dev->struct_mutex);
                 return -ENODEV;
         }