Re: [Letux-kernel] [RFC PATCH 0/3] Enable 1GHz support on omap36xx

From: H. Nikolaus Schaller
Date: Wed Sep 11 2019 - 13:43:26 EST


Hi Adam,

> Am 11.09.2019 um 18:01 schrieb H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>:
>
>>
>> Am 11.09.2019 um 17:56 schrieb Adam Ford <aford173@xxxxxxxxx>:
>>
>>> There are some subtleties for testing.
>>>
>>> * I have added turbo-mode; to OPP6 / OPP1G
>>> * which means they are available but not used by the ondemand govenor
>>> * to enable them one has to echo 1 >/sys/devices/system/cpu/cpufreq/boost
>>
>> Will that be documented somewhere? If not, can we put a comment in the
>> device tree so people know how to enable it?
>
> It seems to be pretty standard on i86 systems if you google for "turbo mode".
> I have added it to the commit message which adds the vbb regulator.

And, I am not sure if DT maintainers will accept comments about the
Linux /sys implementation in device tree files or bindings. Those
should be independent of Linux.

Basically the turbo-mode property is a hint to the OPP system (which
may or may not use of it).

So I think it is indeed better to have it in the commit message and
not the code.

One more thought: as long as we do not have junction temperature monitoring
we should keep it off by default... We may even remove the turbo-mode
designator if we have the 90ÂC limit and smart reflex working.

BR,
Nikolaus