Re: [patch] properly stop devices before poweroff

[Pavel Machek <pavel@ucw.cz>]

Hi!

> > > I started on my OLS homework from Andrew ... and began looking
> > > into what is going on here.
> > > 
> > 
> > Thanks ;) I guess we'll end up with a better kernel, even though you appear
> > to be an innocent victim here.
> 
> The "Badness in iosapic_unregister_intr at arch/ia64/kernel/iosapic.c:851"
> messages are caused by a missing call to free_irq() in the mpt/fusion driver.
> I think that it should go here ... but someone with a clue should verify:
> 
> diff --git a/drivers/message/fusion/mptbase.c b/drivers/message/fusion/mptbase.c
> --- a/drivers/message/fusion/mptbase.c
> +++ b/drivers/message/fusion/mptbase.c
> @@ -1384,6 +1384,8 @@ mpt_suspend(struct pci_dev *pdev, pm_mes
>  	/* Clear any lingering interrupt */
>  	CHIPREG_WRITE32(&ioc->chip->IntStatus, 0);
>  
> +	free_irq(ioc->pci_irq, ioc);
> +
>  	pci_disable_device(pdev);
>  	pci_set_power_state(pdev, device_state);

Looks good, but check with Len Brown. He did relevant ACPI changes.

> But even this doesn't fix the hang during shutdown :-(
> 
> The remaining problem is cause by the order of the calls in sys_reboot:
> 
>                 device_suspend(PMSG_SUSPEND);
>                 device_shutdown();
> 
> The call to device_suspend() shuts down the mpt/fusion driver.  But then
> device_shutdown() calls sd_shutdown() which prints:
> 
>   Synchronizing SCSI cache for disk sdb

Okay, looks to me like sd_shutdown should be done from
device_suspend(), not device_shutdown [because it needs scsi subsystem
to be functional]. Also for reboot we probably want PMSG_FREEZE (not
PMSG_SUSPEND), to keep it slightly faster.

								Pavel
-- 
teflon -- maybe it is a trademark, but it should not be.