drm/i915: Restore GTT mapping first upon resume

As suggested by Daniel Vetter, this is a safeguard should any of the
registers cause reference to PTE entries.

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

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index ad28b21f4d03..2be344a8e93b 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -304,13 +304,18 @@ static int i915_drm_thaw(struct drm_device *dev)
         struct drm_i915_private *dev_priv = dev->dev_private;
         int error = 0;
 
+        if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+                mutex_lock(&dev->struct_mutex);
+                i915_gem_restore_gtt_mappings(dev);
+                mutex_unlock(&dev->struct_mutex);
+        }
+
         i915_restore_state(dev);
         intel_opregion_setup(dev);
 
         /* KMS EnterVT equivalent */
         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
                 mutex_lock(&dev->struct_mutex);
-                i915_gem_restore_gtt_mappings(dev);
                 dev_priv->mm.suspended = 0;
 
                 error = i915_gem_init_ringbuffer(dev);