drm_fb_helper_resume_worker() uses fb_helper->fbdev to call
fb_set_suspend() which dereferences the pointer.
Move sync-canceling of the resume worker in drm_fb_helper_fini() before
setting fb_helper->fbdev to NULL. Move dirty_work as well.
Signed-off-by: NNoralf Trønnes <noralf@tronnes.org>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1503940668-25883-2-git-send-email-noralf@tronnes.org