drm/radeon: don't allow device to be opened if powered down

If the switcheroo has switched the device off, don't let X open it.

Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c
index 5eee3c4..8fbbe1c 100644
--- a/drivers/gpu/drm/radeon/radeon_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_kms.c
@@ -203,6 +203,10 @@
  */
 int radeon_driver_firstopen_kms(struct drm_device *dev)
 {
+	struct radeon_device *rdev = dev->dev_private;
+
+	if (rdev->powered_down)
+		return -EINVAL;
 	return 0;
 }