Revert "drm/fb-helper: Perform damage handling in deferred-I/O helper"

This reverts commit 5fc586a0.

Needed to restore the fbdev damage worker. There have been bug reports
about locking order [1] and incorrectly takens branches. [2] Restore
the damage worker until these problems have been resovled.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://intel-gfx-ci.01.org/tree/drm-tip/fi-kbl-8809g.html # 1
Link: https://lore.kernel.org/dri-devel/20221115115819.23088-6-tzimmermann@suse.de/T/#m06eedc0a468940e4cbbd14ca026733b639bc445a # 2
Link: https://patchwork.freedesktop.org/patch/msgid/20221118133535.9739-4-tzimmermann@suse.de
(cherry picked from commit e3ddd2d2)

drivers/gpu/drm/drm_fb_helper.c

@@ -666,16 +666,10 @@ void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagerefli
 
 	if (min_off < max_off) {
 		drm_fb_helper_memory_range_to_clip(info, min_off, max_off - min_off, &damage_area);
-		drm_fb_helper_add_damage_clip(helper, damage_area.x1, damage_area.y1,
-					      drm_rect_width(&damage_area),
-					      drm_rect_height(&damage_area));
+		drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
+				     drm_rect_width(&damage_area),
+				     drm_rect_height(&damage_area));
 	}
-
-	/*
-	 * Flushes all dirty pages from mmap's pageref list and the
-	 * areas that have been written by struct fb_ops callbacks.
-	 */
-	drm_fb_helper_fb_dirty(helper);
 }
 EXPORT_SYMBOL(drm_fb_helper_deferred_io);