https://bugs.freedesktop.org/show_bug.cgi?id=81382
--- Comment #4 from Denys Vlasenko vda.linux@googlemail.com --- (In reply to comment #3)
Created attachment 102856 [details] [review] set the default backlight level to something reasonable
Does this patch help?
Yes, it does.
Maybe add a comment there why this check is necessary?