Re: [PATCH 06/14] ARM: dts: sun8i: Add cpu0 label to sun8i-h3.dtsi

[Maxime Ripard]

On Sat, Jun 25, 2016 at 09:02:48AM +0800, Chen-Yu Tsai wrote:
> On Sat, Jun 25, 2016 at 6:51 AM, OndÅej Jirman <megous@xxxxxxxxxx> wrote:
> > Hello,
> >
> > comments below.
> >
> > On 24.6.2016 05:48, Chen-Yu Tsai wrote:
> >> On Fri, Jun 24, 2016 at 3:20 AM,  <megous@xxxxxxxxxx> wrote:
> >>> From: Ondrej Jirman <megous@xxxxxxxxxx>
> >>>
> >>> Add label to the first cpu so that it can be referenced
> >>> from derived dts files.
> >>>
> >>> Signed-off-by: Ondrej Jirman <megous@xxxxxxxxxx>
> >>> ---
> >>>  arch/arm/boot/dts/sun8i-h3.dtsi | 2 +-
> >>>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>>
> >>> diff --git a/arch/arm/boot/dts/sun8i-h3.dtsi b/arch/arm/boot/dts/sun8i-h3.dtsi
> >>> index 9938972..82faefc 100644
> >>> --- a/arch/arm/boot/dts/sun8i-h3.dtsi
> >>> +++ b/arch/arm/boot/dts/sun8i-h3.dtsi
> >>> @@ -52,7 +52,7 @@
> >>>                 #address-cells = <1>;
> >>>                 #size-cells = <0>;
> >>>
> >>> -               cpu@0 {
> >>> +               cpu0: cpu@0 {
> >>>                         compatible = "arm,cortex-a7";
> >>>                         device_type = "cpu";
> >>>                         reg = <0>;
> >>
> >> Can you also set the cpu clock here? It is part of the SoC
> >> and does not belong in the board DTS files.
> >
> > Do you mean operating-points, or something else? Different SBCs will
> > probably require different combinations of operating points just for
> > safety's sake, because they have different regulators and [some have
> > botched] thermal designs, so it might make sense to customize it for
> > differnt boards, and I don't feel adventurous enough setting it for all
> > H3 boards out there.
> 
> I meant clocks = <...> and clock-latency = <...>.
> 
> These 2 are part of the SoC.
> 
> The OPP can stay in the board files. It's a pity there's no standard
> OPP table for H3 though. :(

This has never been the case, and we always had some deviation in the
FEX files for all the SoCs.

If we could come up with standard OPPs that work for every one,
there's no reason it can't happen here.

I don't really see why the thermal design should change anything. If a
boards heats faster, it will throttle down to a lower OPP faster, but
those OPPs are not going to change.

Maxime

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

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