On Tue, Jan 20, 2015 at 07:51:31AM +0000, Anson.Huang@xxxxxxxxxxxxx wrote: > > > > +&cpu0 { > > > > + operating-points = < > > > > + /* kHz uV */ > > > > + 996000 1250000 > > > > + 792000 1175000 > > > > + 396000 1075000 > > > > + >; > > > > + fsl,soc-operating-points = < > > > > + /* ARM kHz SOC uV */ > > > > + 996000 1175000 > > > > + 792000 1175000 > > > > + 396000 1175000 > > > > + >; > > > > > > I'm wondering why different revision of the board require a different > > > OPP settings. > > > > > > > Anson, do you know the reason? > > As i.MX6SX SDB Rev-B board uses PFuse 200 which has only one power supply for both > VDDARM_IN and VDDSOC_IN, so it needs VDDARM_IN equal VDDSOC_IN, currently > we set Rev-B board as default in imx6sx.dtsi, which uses same voltage for both > VDDARM_IN and VDDSOC_IN.The Rev-A board uses PFuze 100 which has separate power > supply for VDDARM_IN and VDDSOC_IN, so it can use different voltage on VDDARM_IN > and VDDSOC_IN according to datasheet. Thanks for the clarification, Anson. Peter, OPP is a CPU characteristic defined by data sheet, so we should define OPP according to data sheet in imx6sx.dtsi, and only overwrite the property in Rev-B dts per board/PMIC quirk. Also, please put the rationale why we need OPP quick on Rev-B into commit log. Shawn -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html