Re: [PATCH v5 6/6] qcom/soc/drivers: Add DTPM description for sdm845

Steev Klimaszewski
2021-12-19T18:44:34Z

Hi Daniel,

On 12/18/21 2:11 PM, Daniel Lezcano wrote:
> Hi Steev,
>
> thanks for taking the time to test the series.

My C630 is my daily driver and main computer, so I don't mind testing
things to improve its usage at all.

> <snip>
> Yes, the module is designed to be loaded only. I did not wanted to add
> more complexity in the driver as unloading it is not the priority ATM.
> We need this to be a module in order to load it after the other devices.
Makes sense, I just wasn't entirely sure if it was on purpose or not.
>>> +    depends on DTPM
>>> +    help
>>> +     Describe the hierarchy for the Dynamic Thermal Power
>>> +     Management tree on this platform. That will create all the
>>> +     power capping capable devices.
>>> +
>>>   endmenu
>>> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
>>> index 70d5de69fd7b..cf38496c3f61 100644
>>> --- a/drivers/soc/qcom/Makefile
>>> +++ b/drivers/soc/qcom/Makefile
>>> @@ -28,3 +28,4 @@ obj-$(CONFIG_QCOM_LLCC) += llcc-qcom.o
>>>   obj-$(CONFIG_QCOM_RPMHPD) += rpmhpd.o
>>>   obj-$(CONFIG_QCOM_RPMPD) += rpmpd.o
>>>   obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) +=    kryo-l2-accessors.o
>>> +obj-$(CONFIG_QCOM_DTPM) += dtpm.o
> [ ... ]
I noticed this as well, and was going to ask if it shouldn't be named
qcom_dtpm, but I don't think it matters since it would be in
/lib/modules/$kver/kernel/drivers/soc/qcom ?
>>> +static struct of_device_id __initdata sdm845_dtpm_match_table[] = {
>>> +        { .compatible = "qcom,sdm845", .data = sdm845_hierarchy },
>>> +        {},
>>> +};
>>> +
>>> +static int __init sdm845_dtpm_init(void)
>>> +{
>>> +    return dtpm_create_hierarchy(sdm845_dtpm_match_table);
>>> +}
>>> +late_initcall(sdm845_dtpm_init);
>>> +
>>> +MODULE_DESCRIPTION("Qualcomm DTPM driver");
>>> +MODULE_LICENSE("GPL");
>>> +MODULE_ALIAS("platform:dtpm");
>>> +MODULE_AUTHOR("Daniel Lezcano <daniel.lezcano@kernel.org");
>>> +
>> It does seem to work aside from not being able to modprobe -r the
>> module. Although I do see
>>
>> [   35.849622] dtpm: Registered dtpm node 'sdm845' / 0-0 uW,
>> [   35.849652] dtpm: Registered dtpm node 'package' / 0-0 uW,
>> [   35.849676] dtpm: Registered dtpm node 'cpu0-cpufreq' / 40000-436000 uW,
>> [   35.849702] dtpm: Registered dtpm node 'cpu4-cpufreq' /
>> 520000-5828000 uW,
>> [   35.849734] dtpm_devfreq: No energy model available for '5000000.gpu'
>> [   35.849738] dtpm: Failed to setup '/soc@0/gpu@5000000': -22
>>
>> If the devfreq issue with the gpu isn't expected, are we missing
>> something for the c630?
> Yes, the energy model is missing for the GPU, very likely the
> 'dynamic-power-coefficient' property is missing in the gpu section.
>
> A quick test could be to add a value like 800. The resulting power
> numbers will be wrong but it should be possible to act on the
> performance by using these wrong power numbers.
>
> -- Daniel
>
So, I'm definitely not the greatest of kernel hackers, just enough
knowledge to be dangerous and I know how to apply patches properly....
I'm not able to actually get this working.  I've tried adding it with a
few different numbers, and any time i try to add the d-p-c, I get

Dec 18 15:00:49 limitless kernel: [   57.394503] adreno 5000000.gpu: EM:
invalid perf. state: -22
Dec 18 15:00:49 limitless kernel: [   57.394515] dtpm_devfreq: No energy
model available for '5000000.gpu'
Dec 18 15:00:49 limitless kernel: [   57.394519] dtpm: Failed to setup
'/soc@0/gpu@5000000': -22

-- steev