Re: cpufreq implementation for OMAP under xen hypervisor.

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Mon, Sep 29, 2014 at 12:45:36PM +0300, Oleksandr Dmytryshyn wrote:
> On Fri, Sep 26, 2014 at 9:13 PM, Konrad Rzeszutek Wilk
> <konrad.wilk@oracle.com> wrote:
> >
> > > > The architecture looks sane to me. As Konrad pointed out, the difficulty
> > > > here is to be able to upstream the changes to the Linux driver in 2),
> > > > that you later in the thread identified as
> > > > drivers/cpufreq/cpufreq-cpu0.c.
> > > I'll write driver drivers/xen/xen-cpufreq.c and it replace original
> > > drivers/cpufreq/cpufreq.c
> > > And in the original cpufreq-cpu0 driver I'll chande only one string -
> > > path in the device tree
> > > with the settings for the CPUs opp:
> > > string
> > > np = of_find_node_by_path("/cpus/cpu@0");
> > > will changed to:
> > > np = of_find_node_by_path("/cpus/cpu@0/private_data/cpu@0");
> > >
> > > > If the changes are not invasive and you manage to upstream them in
> > > > Linux, I am all for this solution.
> > > In Linux kernel I should make few changes:
> > > 1. Enable CONFIG_CPU_FREQ_TABLE
> > > with disabled CONFIG_CPU_FREQ
> > > 2. Enable CONFIG_GENERIC_CPUFREQ_CPU0
> > > with disabled CONFIG_CPU_FREQ
> > >
> > > I mean make those configs dependent on
> > > CONFIG_CPU_FREQ or CONFIX_XEN_DOM0
> > > instead of
> > > CONFIG_CPU_FREQ
> >
> > Gosh no. Please make it work runtime.
> Sorry, Konrad, could You please explain what did You mean.

Don't make XEN options disable other options.

Distributions want one kernel that can satisfi a variety of platforms - not just specifc ones.