[U-Boot] [PATCH v1 0/4] Jetson-TK1 support for PSCI

Thierry Reding
2015-01-15T14:55:41Z

On Wed, Jan 14, 2015 at 08:58:41AM +0000, Ian Campbell wrote:
> On Wed, 2015-01-14 at 08:57 +0100, Thierry Reding wrote:
> > > I also pushed my tree to gitorious:
> > > https://gitorious.org/ijc/u-boot jetson-psci-v1
> > >
> > > I would Ack your patch, but I don't think you've posted it and it has no
> > > S-o-b so that would seem a bit premature/rude of me. For the same reason
> > > I've not actually included it in the series posted (but it is in the
> > > gitorious branch).
> >
> > Feel free to take ownership of that patch. I currently don't have the
> > time to work on this and it seems you've made good progress on it.
>
> Will do. Could you offer a S-o-b for it please so I can pick it up.

Sure:

Signed-off-by: Thierry Reding <treding@nvidia.com>

> > It could probably use some cleanup because there's a bit of debug output
> > still in there. Also...
> >
> > > FWIW I think you could drop your stub versions of psci_cpu_off and
> > > psci_cpu_suspend (assuming you don't want to implement them) since the
> > > common code has stubs.
> >
> > ... I'd think you'd need to implement these so that you can get proper
> > suspend/resume support in the kernel. I've had to disable cpuidle (via
> > #undef CONFIG_PM_SLEEP in arch/arm/mach-tegra/cpuidle-tegra114.c) in the
> > kernel to make that code not powergate CPUs. Ideally I think the kernel
> > would check that it's running with PSCI support and disable the cpuidle
> > driver. Maybe that could be done by introducing a new cpuidle driver
> > that checks for PSCI availability and uses it when present.
>
> Hrm, I'm not sure how this all fits together, it's not a problem I've
> noted before.
>
> FWIW I think cpu_off and cpu_suspend are optional in PSCI v0.1 so an
> initial version doesn't necessarily need to implement them (sunxi
> doesn't for example), but as you say they do enable useful features.

I think when I tried last time, without disable the cpuidle driver
things would hang at boot. I would expect that problem to exist for
any board. Perhaps you've disabled PM_SLEEP in your config?

Thierry
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