Re: [PATCH v2 0/6] ARM: berlin: add cpufreq support

From: Antoine Tenart
Date: Wed Aug 19 2015 - 04:18:20 EST


On Tue, Aug 18, 2015 at 08:29:25PM +0530, Viresh Kumar wrote:
> On 18-08-15, 16:39, Antoine Tenart wrote:
> > However, it seems the OPP-v2 table takes precedence over the old one.
> > When a default OPP-v2 table is supplied in the device tree, if the
> > bootloader supplies an OPP table the old way it won't be taken into
> > account.
> >
> > So if I understood correctly, this won't work here for the BG2Q.
>
> Didn't understood it completely. Are you saying that your dtb will
> have two operating-points tables ?

Yes. If the device tree has an OPP-v2 table and the bootloader modify it
to add an old OPP table at boot, the one added by the bootloader won't
be taken into account by the kernel.

> The deal is that for any device, parsing of opp-v2 will be attempted
> first. If its not available, then opp-v1 will be tried. But this is
> per-device. So, one device can have opp-v2 tables and other one can do
> v1 type.

Sure. OPP-v2 tables can be used for devices having an up-to-date
bootloader or if the bootloader do not modify the device tree at boot
time to add an (old) OPP table.

Antoine

--
Antoine Ténart, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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