Re: [RFC/RFT v3 11/14] arm64: dts: meson-g12a: add cpus OPP table

Hi Neil,

On Wed, Jul 3, 2019 at 1:53 PM Neil Armstrong [off-list ref] wrote:

On 03/07/2019 01:47, Martin Blumenstingl wrote:

quoted

Hi Neil,

On Mon, Jul 1, 2019 at 11:13 AM Neil Armstrong [off-list ref] wrote:

quoted

Add the OPP table taken from the vendor u200 and u211 DTS.

The Amlogic G12A SoC seems to available in 3 types :
- low-speed: up to 1,8GHz
- mid-speed: up to 1,908GHz
- high-speed: up to 2.1GHz

And the S905X2 opp voltages are slightly higher than the S905D2
OPP voltages for the low-speed table.

This adds the conservative OPP table with the S905X2 higher voltages
and the maximum low-speed OPP frequency.

have you considered all three as separate voltage tables?
you're other patches are assigning the OPP table to the CPU in the
board.dts anyways, so it's easy to use different OPP tables for
different boards

We can't assume the board and the CPU type :-/

OK, should we assign the OPP table to the CPU cores then in the
soc.dtsi (instead of board.dts like the other patches from this series
do)?

Kevin told me about cpufreq policy, where we could add a policy reading the
eFUSE and changing the max frequency, then we could add the whole OPP table.

we can still do that in a second step, so I'm all for starting with
the "conservative" OPP table and then improve performance (by having
detecting the SoC and using the correct OPP table)


Martin

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