On Sat, 11 Feb 2006, Pavel Machek wrote:
> On Pá 10-02-06 14:59:58, Randy.Dunlap wrote:
> > On Fri, 10 Feb 2006, Pavel Machek wrote:
> >
> > > Hi!
> > >
> > > > in Documentation/power/devices.txt, I read:
> > > >
> > > > <quote>
> > > > System shutdown -- at least disks need to be spun down, or data may be
> > > > lost. Quiesce devices, just to make life easier for BIOS. event =
> > > > FREEZE, flags = SYSTEM_SHUTDOWN
> > > > </quote>
> > > >
> > > > Is this actually done somewhere? I can't find /SYSTEM_SHUTDOWN/
> > > > in any kernel .h or .c files.
> > >
> > > I think we do FREEZE during shutdown, but flags never got
> > > implemented. It seems nobody really needs them, so...
> >
> > I'm not particular about the flags, but I do have a case of
> > needing to do what the comment describes: spin down disks
> > during shutdown. Can anyone suggest how that should be done?
> >
> > [I'm currently adding code to use register_reboot_notifier()
> > and keeping a table of SATA/PATA controllers/channels for use
> > at shutdown...]
>
> No, that is not the right way.
>
> void kernel_shutdown_prepare(enum system_states state)
> {
> notifier_call_chain(&reboot_notifier_list,
> (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
> system_state = state;
> device_shutdown();
> }
>
> device_shutdown() should do it, AFAICT.
>
> If you want to listen to such event, you should just register your
> driver with sysfs and implement .suspend() method. But I believe PATA
> does that already...
I walked thru that code path and didn't see it happening.
And for PATA, please expect libata, not legacy drivers/ide/.
--
~Randy
