On Thu, Mar 07, 2019 at 10:39:23AM +0100, Geert Uytterhoeven wrote: > On Thu, Mar 7, 2019 at 10:00 AM Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> wrote: > > It's possible to do this using a reboot notifier. I am not sure if there > > are better ways to achieve the same, but there's at least one example of > > using reboot notifiers to achieve the exact same goal. > > > > See drivers/video/fbdev/aty/atyfb_base.c, look for > > register_reboot_notifier(). > > Or a shutdown handler, which is more device-centric? > (cfr. "[3/4] fbdev: atafb: Fix broken frame buffer after kexec", > https://patchwork.kernel.org/patch/10814381/). > > Gr{oetje,eeting}s, Thanks, I knew reboot_notifier but I thought it feels "hacky" to use it in a device driver, shutdown() handler looks better. Nevertheless, does it mean there's no way to prevent it from happening if the user issues a emergency reboot? Like an automatic reboot after a kernel panic, or a SysRq-B reboot. Tom Li