Messages in this thread | | | Date | Fri, 16 Jul 2021 15:52:12 -0500 | From | Bjorn Andersson <> | Subject | Re: [PATCH v4 2/2] arm64: dts: sc7180: Add required-opps for i2c |
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On Fri 16 Jul 15:21 CDT 2021, Stephen Boyd wrote:
> Quoting Bjorn Andersson (2021-07-16 13:18:56) > > On Fri 16 Jul 05:00 CDT 2021, Rajendra Nayak wrote: > > > > > qup-i2c devices on sc7180 are clocked with a fixed clock (19.2 MHz) > > > Though qup-i2c does not support DVFS, it still needs to vote for a > > > performance state on 'CX' to satisfy the 19.2 Mhz clock frequency > > > requirement. > > > > > > > Sounds good, but... > > > > > Use 'required-opps' to pass this information from > > > device tree, and also add the power-domains property to specify > > > the CX power-domain. > > > > > > > ..is the required-opps really needed with my rpmhpd patch in place? > > > > Yes? Because rpmhpd_opp_low_svs is not the lowest performance state for > CX.
On e.g. sm8250 the first available non-zero corner presented in cmd-db is low_svs.
And if this (which?) clock requires a higher corner than the lowest possible in order to tick at this "lowest" frequency, I'm certainly interested in some more details.
Regards, Bjorn
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