drm/i915: Be paranoid and bail on resetting if we can't take the lock.

This will declare the machine wedged, but is better than truly wedging
the machine.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 1a15b7886b8c..64844e2e9f86 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -440,7 +440,8 @@ int i915_reset(struct drm_device *dev, u8 flags)
         bool need_display = true;
         int ret;
 
-        mutex_lock(&dev->struct_mutex);
+        if (!mutex_trylock(&dev->struct_mutex))
+                return -EBUSY;
 
         i915_gem_reset(dev);