Re: Cpufreq regression in next-20161207

Tero Kristo
2016-12-08T08:54:15Z

On 08/12/16 08:04, Tony Lindgren wrote:
> * Viresh Kumar <viresh.kumar@linaro.org> [161207 21:58]:
>> On 07-12-16, 21:52, Tony Lindgren wrote:
>>> Hmm good question. Maybe we don't have the regulators configured for
>>> pandaboard?
>>
>> Hmm, and who would be the right person to confirm that? And its not only about
>> pandaboard but the whole OMAP4 family (which is using cpufreq-dt driver).
>
> Nishanth and Dave in Cc should be able to confirm. Most likely it's some
> missing .config option for the regulators in multi_v7_defconfig compared
> to omap2plus_defconfig though.
>
> Regards,
>
> Tony

Pandaboard has a weird configuration, where MPU VDD is controlled by a
separate component; TPS62361, but rest of the voltages are provided by
TWL6030. The support for this was attempted to be upstreamed along with
the required changes for the VC/VP framework under mach-omap2, but this
was never accepted.

I'm not sure but I recall it wasn't possible to control the MPU voltage
via the default I2C interface, instead you had to use the VC/VP path,
which isn't fully implemented for OMAP4. As a consequence, none of the
OMAP4 boards have a properly functioning MPU voltage supply control in
place and you will rely on u-boot provided voltages.

-Tero