[Intel-gfx] [PATCH] take struct mutex around fb unref

[Jesse Barnes]

Need to do this in case the unref ends up doing a free.

Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index bbdd729..b6e8af5 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1598,7 +1598,9 @@ intel_user_framebuffer_create(struct drm_device *dev,
 
 	ret = intel_framebuffer_create(dev, mode_cmd, &fb, obj);
 	if (ret) {
+		mutex_lock(&dev->struct_mutex);
 		drm_gem_object_unreference(obj);
+		mutex_unlock(&dev->struct_mutex);
 		return NULL;
 	}