Re: [RFC-next 0/1] Odroid C2: Enable DVFS for cpu

From: Neil Armstrong
Date: Tue Dec 10 2019 - 03:43:35 EST


On 09/12/2019 23:12, Kevin Hilman wrote:
> Anand Moon <linux.amoon@xxxxxxxxx> writes:
>
>> Some how this patch got lost, so resend this again.
>>
>> [0] https://patchwork.kernel.org/patch/11136545/
>>
>> This patch enable DVFS on GXBB Odroid C2.
>>
>> DVFS has been tested by running the arm64 cpuburn
>> [1] https://github.com/ssvb/cpuburn-arm/blob/master/cpuburn-a53.S
>> PM-QA testing
>> [2] https://git.linaro.org/power/pm-qa.git [cpufreq testcase]
>>
>> Tested on latest U-Boot 2019.07-1 (Aug 01 2019 - 23:58:01 +0000) Arch Linux ARM
>
> Have you tested with the Harkernel u-boot?
>
> Last I remember, enabling CPUfreq will cause system hangs with the
> Hardkernel u-boot because of improperly enabled frequencies, so I'm not
> terribly inclined to merge this patch.

Same, since the bootloader boots with the max supported freq of the board,
there is not real need of DVFS except for specific low-power use-cases.

And still, some early boards still use the bad SCPI freq table, we can't break them.

Neil

>
>> Patch based on my next-20191031 for 5.5.x kernel.
>> Hope this is not late entry.
>
> Re: "too late". FYI... when you post things as RFC, it means you're
> looking for comments (Request For Comment) but that it's not intended
> for merging.
>
> I didn't see any comments on this, but I also didn't see a non-RFC
> follow-up, so I didn't queue it for v5.5.
>
> Kevin
>