linux-kernel - Re: [PATCH v4 4/5] cpufreq: qcom-cpufreq-hw: Use new thermal pressure update function

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Message-ID: <8239b35e-8f51-e36c-96c6-4e5d986eebf9@arm.com>
Date:   Tue, 16 Nov 2021 08:30:25 +0000
From:   Lukasz Luba <lukasz.luba@....com>
To:     Thara Gopinath <thara.gopinath@...aro.org>
Cc:     linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-arm-msm@...r.kernel.org, steev@...i.org,
        sudeep.holla@....com, will@...nel.org, catalin.marinas@....com,
        linux@...linux.org.uk, gregkh@...uxfoundation.org,
        rafael@...nel.org, viresh.kumar@...aro.org, amitk@...nel.org,
        daniel.lezcano@...aro.org, amit.kachhap@...il.com,
        bjorn.andersson@...aro.org, agross@...nel.org
Subject: Re: [PATCH v4 4/5] cpufreq: qcom-cpufreq-hw: Use new thermal pressure
 update function



On 11/15/21 8:57 PM, Thara Gopinath wrote:
> 
> 
> On 11/9/21 2:57 PM, Lukasz Luba wrote:
>> Thermal pressure provides a new API, which allows to use CPU frequency
>> as an argument. That removes the need of local conversion to capacity.
>> Use this new API and remove old local conversion code.
>>
>> The new arch_update_thermal_pressure() also accepts boost frequencies,
>> which solves issue in the driver code with wrong reduced capacity
>> calculation. The reduced capacity was calculated wrongly due to
>> 'policy->cpuinfo.max_freq' used as a divider. The value present there was
>> actually the boost frequency. Thus, even a normal maximum frequency value
>> which corresponds to max CPU capacity (arch_scale_cpu_capacity(cpu_id))
>> is not able to remove the capping.
> 
> Yes, although cpuinfo.max_freq does not reflect the boost frequency 
> unless boost is enabled atleast once. I have sent a patch to fix this. 
> But I agree that using cpuinfo.max_freq has issues you have mentioned in 
> this patch if boost is enabled once.
> 
> So, for this patch
> 
> Reviewed-by: Thara Gopinath <thara.gopinath@...aro.org>

Thank you for the review!

> 
> Warm Regards
> Thara (She/Her/Hers)