[PATCH V3 0/6] ARM64: Add support for FSL's LS2085A SoC

bhupesh.sharma at freescale.com
2014-09-03T15:42:07Z

> -----Original Message-----
> From: Arnd Bergmann [mailto:arnd at arndb.de]
> Sent: Wednesday, September 03, 2014 9:09 PM
> To: Sharma Bhupesh-B45370
> Cc: Catalin.Marinas at arm.com; Will.Deacon at arm.com;
> grant.likely at secretlab.ca; mark.rutland at arm.com; marc.zyngier at arm.com;
> rob.herring at linaro.org; linux-arm-kernel at lists.infradead.org; Yoder
> Stuart-B08248; Basu Arnab-B45036
> Subject: Re: [PATCH V3 0/6] ARM64: Add support for FSL's LS2085A SoC
>
> On Wednesday 03 September 2014 15:36:44 bhupesh.sharma at freescale.com
> wrote:
> > > On Wednesday 03 September 2014 20:43:08 Bhupesh Sharma wrote:
> > > >
> > > > In this version, the enable-method for the CPU nodes is left for
> > > > the bootloader (u-boot or UEFI) to patch-up. This DTS has been
> > > > tested for PSCI v0.2 CPU_ON method (and corresponding secondary
> > > > boot) using the following ARMv8 u-boot patches:
> > >
> > > What would be a reason for using something other than PSCI?
> > >
> >
> > We had originally gone ahead and implemented spin-table release method
> > in ARMv8 u-boot (see [1]) (the v3 of that patchset is still in works),
> > but we have since been pointed towards PSCI by Mark and Catalin, so we
> > have implemented PSCI in ARMv8 u-boot and the v2 and v3 of the DTS
> patchset have been tested with both the spin-table and PSCI approaches.
> >
> > [1] http://lists.denx.de/pipermail/u-boot/2014-June/182759.html
> >
>
> Would it be possible then to just mandate PSCI for the upstream-supported
> version?

Yes. The upstream DTS is going to use PSCI as the default cpu release method
for the secondary's. Later as we add more richness to the PSCI v0.2 layer
in the ARMv8 u-boot, we will look to check features such as Hotplug etc.

Regards,
Bhupesh