drm/radeon: restore the fbdev mode in lastclose

restore the fbdev state if a drm app like X is killed.

Tested-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_fb.c

@@ -397,3 +397,19 @@ void radeon_fb_remove_connector(struct radeon_device *rdev, struct drm_connector
 {
 	drm_fb_helper_remove_one_connector(&rdev->mode_info.rfbdev->helper, connector);
 }
+
+void radeon_fbdev_restore_mode(struct radeon_device *rdev)
+{
+	struct radeon_fbdev *rfbdev = rdev->mode_info.rfbdev;
+	struct drm_fb_helper *fb_helper;
+	int ret;
+
+	if (!rfbdev)
+		return;
+
+	fb_helper = &rfbdev->helper;
+
+	ret = drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper);
+	if (ret)
+		DRM_DEBUG("failed to restore crtc mode\n");
+}

drivers/gpu/drm/radeon/radeon_kms.c

@@ -598,14 +598,17 @@ static int radeon_info_ioctl(struct drm_device *dev, void *data, struct drm_file
  * Outdated mess for old drm with Xorg being in charge (void function now).
  */
 /**
- * radeon_driver_firstopen_kms - drm callback for last close
+ * radeon_driver_lastclose_kms - drm callback for last close
  *
  * @dev: drm dev pointer
  *
  * Switch vga switcheroo state after last close (all asics).
  */
 void radeon_driver_lastclose_kms(struct drm_device *dev)
 {
+	struct radeon_device *rdev = dev->dev_private;
+
+	radeon_fbdev_restore_mode(rdev);
 	vga_switcheroo_process_delayed_switch();
 }
 

drivers/gpu/drm/radeon/radeon_mode.h

@@ -980,6 +980,7 @@ int radeon_fbdev_init(struct radeon_device *rdev);
 void radeon_fbdev_fini(struct radeon_device *rdev);
 void radeon_fbdev_set_suspend(struct radeon_device *rdev, int state);
 bool radeon_fbdev_robj_is_fb(struct radeon_device *rdev, struct radeon_bo *robj);
+void radeon_fbdev_restore_mode(struct radeon_device *rdev);
 
 void radeon_fb_output_poll_changed(struct radeon_device *rdev);