Re: Shutdown problem in SMP system happened on Tegra20

From: Russell King - ARM Linux
Date: Sat Aug 25 2012 - 03:18:08 EST


On Sat, Aug 25, 2012 at 08:00:56AM +0800, Bill Huang wrote:
> nvpublic
> > So what you're asking for is a feature to do what CONFIG_PM_SLEEP_SMP does, but without
> > CONFIG_PM_SLEEP_SMP enabled?
>
> Yeah pretty much, I'm actually asking should we take care of this since maybe not all platforms
> will have this config enabled?
> >
> > Why not just ensure that CONFIG_PM_SLEEP_SMP is enabled if your platform requires that the lowest CPU
> > number be the CPU dealing with reboot?
>
> Someday we will have it enabled, but before that we'll hit the issue, so you don't think
> this should be taken care of? Thanks.

Well, just enable CONFIG_PM_SLEEP_SMP then - it'll be far better than
trying to implement something in the ARM code, especially as sysrq can
be used for poweroff/reboot etc (which will run from atomic contexts
where you can't switch to another CPU.)

What you're asking for will make these callbacks fragile for other
platforms.
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