31.08.2020 14:04, Viresh Kumar пишет: > On 31-08-20, 12:54, Dmitry Osipenko wrote: >> It's not clear to me how it could be applicable to the Tegra CPU OPP >> because Tegra depends on a combination of SPEEDO + PROCESS versions. >> >> It's not like all voltages are the same for all OPPs that have the same >> PROCESS ID, otherwise it indeed would be nice to have >> "opp-microvolt-process0", but unfortunately this variant is not suitable >> for Tegra because some freqs have different voltages using the same >> PROCESS ID and the same applies to the SPEEDO ID. > > How exactly do you know what voltage belongs to a particular OPP ? >From these tables: https://nv-tegra.nvidia.com/gitweb/?p=linux-2.6.git;a=blob;f=arch/arm/mach-tegra/tegra2_dvfs.c;hb=l4t/l4t-r16-r2#l157 https://nv-tegra.nvidia.com/gitweb/?p=linux-2.6.git;a=blob;f=arch/arm/mach-tegra/tegra3_dvfs.c;hb=l4t/l4t-r16-r2#l148 > opp@216000000 { > clock-latency-ns = <400000>; > opp-supported-hw = <0x0F 0x0003>; > opp-hz = /bits/ 64 <216000000>; > opp-microvolt-fast-process0 = <750000 750000 1125000>; > opp-microvolt-slow-process0 = <750000 850000 1125000>; > > }; > > opp@312000000 { > clock-latency-ns = <400000>; > opp-supported-hw = <0x0F 0x0003>; > opp-hz = /bits/ 64 <312000000>; > opp-microvolt-fast-process0 = <750000 750000 1125000>; > opp-microvolt-slow-process0 = <750000 850000 1125000>; > }; > > You can make any combinations of such names that come from speedo, > process, or something else. If you can get this done as a fixed > formula then it is workable. > IIUC, there is no fixed formula for Tegra, at least I don't see it. For example, if you'll take a look at the 1300MHz OPP of Tegra30, then you could see that this freq has a lot of voltages each depending on specific combination of SPEEDO+PROCESS versions.
