31.08.2020 14:04, Viresh Kumar пишет:

On 31-08-20, 12:54, Dmitry Osipenko wrote:

quoted

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.