Hi, Leonard > On 7/4/2019 9:23 AM, Anson.Huang@xxxxxxx wrote: > > From: Anson Huang <Anson.Huang@xxxxxxx> > > > > Assign highest OPP as suspend OPP to reduce suspend/resume latency on > > i.MX8MM. > > > > Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx> > > --- > > arch/arm64/boot/dts/freescale/imx8mm.dtsi | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/arch/arm64/boot/dts/freescale/imx8mm.dtsi > > b/arch/arm64/boot/dts/freescale/imx8mm.dtsi > > index b11fc5e..3a62407 100644 > > --- a/arch/arm64/boot/dts/freescale/imx8mm.dtsi > > +++ b/arch/arm64/boot/dts/freescale/imx8mm.dtsi > > @@ -136,6 +136,7 @@ > > opp-microvolt = <1000000>; > > opp-supported-hw = <0x8>, <0x3>; > > clock-latency-ns = <150000>; > > + opp-suspend; > > }; > > }; > > What if the highest OPP is unavailable due to speed grading? Ideally we > should find a way to suspend at the highest *supported* OPP. > > Maybe the opp-suspend marking could be assigned from imx-cpufreq-dt > driver code? Yes, this is also my concern, the current OPP driver does NOT handle it well, and I was thinking to assigne it from imx-cpufreq-dt driver, 1 option is to runtime add "suspend-opp" property into DT OPP node after parsing the speed grading fuse and OPP table, but I do NOT like that very much, as we need to manually create a property, the other option is to change cpu freq policy inside imx-cpufreq-dt driver in suspend/resume callback? Which one do you prefer? Thanks, Anson > > -- > Regards, > Leonard
