drm: allow open of dynamic off devices.

Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_fops.c

@@ -219,7 +219,7 @@ static int drm_open_helper(struct inode *inode, struct file *filp,
 		return -EBUSY;	/* No exclusive opens */
 	if (!drm_cpu_valid())
 		return -EINVAL;
-	if (dev->switch_power_state != DRM_SWITCH_POWER_ON)
+	if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
 		return -EINVAL;
 
 	DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);

include/drm/drmP.h

@@ -1220,6 +1220,7 @@ struct drm_device {
 #define DRM_SWITCH_POWER_ON 0
 #define DRM_SWITCH_POWER_OFF 1
 #define DRM_SWITCH_POWER_CHANGING 2
+#define DRM_SWITCH_POWER_DYNAMIC_OFF 3
 
 static __inline__ int drm_core_check_feature(struct drm_device *dev,
 					     int feature)