Re: [PATCH] PCI: Add pci shutdown ability

Pavel Machek
2005-04-26T10:13:22Z

Hi!

> > > Actually this patch should be in the queue somewhere... We had it in
> > > suse trees for a long time, and IMO it can solve problem easily.
> > >
> > > Pavel
> > >
> > > --- clean-git/kernel/sys.c 2005-04-23 23:21:55.000000000 +0200
> > > +++ linux/kernel/sys.c 2005-04-24 00:20:47.000000000 +0200
> > > @@ -404,6 +404,7 @@
> > > case LINUX_REBOOT_CMD_HALT:
> > > notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);
> > > system_state = SYSTEM_HALT;
> > > + device_suspend(PMSG_SUSPEND);
> > > device_shutdown();
> >
> > Again, why keep device_shutdown() around at all then?
>
> I've argued for folding shutdown and suspend for some time now, though
> some drivers who rely on shutdown today will need fixing I suppose.
>
> Also, I think kexec shouldn't use "shutdown" but a different message.
> There are some conceptual differences, things like stopping the platters
> on disk etc... things you want to do on one and not the other. In a way,
> kexec needs are very similar to suspend-to-disk "freeze" state. I'd
> rather call PMSG_FREEZE there.

Agreed. If hardware is going to be physically powered down, we need
PMSG_SUSPEND. If it is not (kexec), PMSG_FREEZE should be enough.

Now, if we want separate PMSG_SHUTDOWN. ... I think it is similar
enough to PMSG_SUSPEND that we can keep them same "major" value and
just use different flags. I do not think many drivers will
care.
Pavel
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