Re: [PATCH V2] arm64: dts: qcom: sc7280: Add nodes for eMMC and SD card

[sbhanu]

On 2021-03-29 20:26, Doug Anderson wrote:
> Hi,
>
> On Thu, Mar 25, 2021 at 11:57 PM <sbhanu@xxxxxxxxxxxxxx> wrote:
> > >>> +                       max-frequency = <192000000>;
> > >> Why do you need to specify this?
> > This helps to avoid lower speed modes running in high clock rate,
> > and As Veerabhadrarao Badiganti mentioned
>
> Just to be clear, both Stephen and I agree that you should remove
> "max-frequency" here (see previous discussion). Bjorn is, of course,
> the file decision maker. However, unless he says "yeah, totally keep
> it in" I'd suggest dropping it from the next version.
sure will drop in next version.
> > >>> +                                       required-opps =
> > >>> <&rpmhpd_opp_low_svs>;
> > >>> +                                       opp-peak-kBps = <1200000
> > >>> 76000>;
> > >>> +                                       opp-avg-kBps = <1200000
> > >>> 50000>;
> > >> Why are the kBps numbers so vastly different than the ones on sc7180
> > >> for the same OPP point. That implies:
> > >>
> > >> a) sc7180 is wrong.
> > >>
> > >> b) This patch is wrong.
> > >>
> > >> c) The numbers are essentially random and don't really matter.
> > >>
> > >> Can you identify which of a), b), or c) is correct, or propose an
> > >> alternate explanation of the difference?
> > >>
> >
> > We calculated bus votes values for both sc7180 and sc7280 with ICB 
> > tool,
> > above mentioned values we got for sc7280.
>
> I don't know what an ICB tool is. Please clarify.
>
> Also: just because a tool spits out numbers that doesn't mean it's
> correct. Presumably the tool could be wrong or incorrectly configured.
> We need to understand why these numbers are different.
we checked with ICB tool team on this they conformed as Rennell & Kodiak 
are different chipsets,
we might see delta in ib/ab values due to delta in scaling factors.

> -Doug