problems getting AMD C-70 APU working with powerd/cpufreq

[Anthony Jenkins]

On 10/16/2017 08:17, tech-lists wrote:
> Hi,
>
> On Mon, Oct 16, 2017 at 02:58:10AM +1100, Ian Smith wrote:
>> On Sat, 14 Oct 2017 22:26:02 +0100, tech-lists wrote:
>> > On Sat, Oct 14, 2017 at 10:36:02PM +1100, Ian Smith wrote:
>> > > On Fri, 13 Oct 2017 13:37:21 +0100, tech-lists wrote:
>
>> However, this is after you've booted, right?  Might you need to add
>> cpufreq_load="YES" to /boot/loader.conf, so it's loaded before being
>> needed for detection / attachment during boot probing, perhaps?
>
> ok tried that. I get cpufreq.ko loaded in the kernel via
> /boot/loader.conf but still I get
>
> $ sudo powerd -v
> powerd: no cpufreq(4) support -- aborting: No such file or directory
>
cpufreq(4) does not support AMD processor family 0x14 (20), which I
believe your dmesg showed your processor to be.
I had added support for controlling the frequency on some later AMD
families last year, but the AMD documentation for the 0x14 family is
pretty complicated for my tiny brain.  The other families control
processor frequency with a single register, but AFACT you use P-states
on family 0x14.  You can have up to 8 P-states, each of which specifies
a power/frequency configuration.  If someone could point me to a
reference for controlling the frequency for this family, I could submit
something for review...no idea what Linux does for this family.

Anthony