Re: what handles disk drive(s) shutdown?

[Pavel Machek <pavel@ucw.cz>]

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...
								Pavel
-- 
Web maintainer for suspend.sf.net (www.sf.net/projects/suspend) wanted...