what handles disk drive(s) shutdown?

what handles disk drive(s) shutdown?

[Randy.Dunlap]

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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.

Thanks,
-- 
~Randy

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Re: what handles disk drive(s) shutdown?

[Alan Stern]

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On Thu, 9 Feb 2006, Randy.Dunlap wrote:

> 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.

Just about everything concerning the flags in those documentation files is 
fictitious.  The flags field doesn't even exist!  Right now there's 
nothing but the event field.

I guess it's what Pavel intended to implement eventually.  That doesn't 
mean the final version will actually take the form described in the 
file...

Alan Stern


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Re: what handles disk drive(s) shutdown?

[Pavel Machek]

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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...

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

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Re: what handles disk drive(s) shutdown?

[Randy.Dunlap]

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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...]

Thanks,
-- 
~Randy

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Re: what handles disk drive(s) shutdown?

[Pavel Machek]

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...

Re: what handles disk drive(s) shutdown?

[Randy.Dunlap]

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

Re: what handles disk drive(s) shutdown?

[Pavel Machek]

On Pá 10-02-06 15:08:26, Randy.Dunlap wrote:
> 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/.

I think drivers/ide does it right. Feel free to copy it :-).
								Pavel
-- 
Web maintainer for suspend.sf.net (www.sf.net/projects/suspend) wanted...

Re: what handles disk drive(s) shutdown?

[Dmitry Torokhov]

On Friday 10 February 2006 18:06, Pavel Machek wrote:
> 
> 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...

You mean .shutdown() method, not .suspend(), right?

-- 
Dmitry

Re: what handles disk drive(s) shutdown?

[Pavel Machek]

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> > 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...
> 
> You mean .shutdown() method, not .suspend(), right?
yep, sorry.
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