Re: [PATCH] arm64: tegra: Add CPU and PSCI nodes for NVIDIA Tegra210 platforms

[Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>]

On Tue, Mar 28, 2017 at 05:49:41PM +0100, Jon Hunter wrote:
> 
> On 28/03/17 17:23, Stephen Warren wrote:
> > On 03/28/2017 05:48 AM, Jon Hunter wrote:
> >> Add the CPU and PSCI nodes for the NVIDIA Tegra210 platforms so that
> >> all CPUs can be enabled on boot. This assumes that the PSCI firmware
> >> has been loaded during the initial bootstrap on the device before the
> >> kernel starts (which is typically the case for these platforms). The
> >> PSCI firmware version is set to v0.2 which aligns with the current
> >> shipping version for Tegra.
> > 
> > This seems fine, although I'd expect PSCI to be used everywhere on
> > Tegra, so putting this in tegra210.dtsi would make more sense.
> 
> It's fine with me. Although technically, tegra210-smaug ships with
> psci-v1.0 and tegra210-jetson-tx1 currently have psci-v0.2. However, I
> did test both with the psci version set to v1.0 and the jetson-tx1, did
> detect the version automatically and reverted to v0.2 (which is a
> feature of psci >= v0.2). 

Please don't rely upon that.

If the DT lists 0.2 and the FW reports 1.0 we deliberately upgrade and
treat it as 1.0, but the other way around was not a deliberate decision.

If the FW is not necessarily 1.0, please do not list 1.0 in the DT.

Thanks,
Mark.
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