Subject: Re: [PATCH v4 4/5] cpufreq: qcom-cpufreq-hw: Use new thermal pressure
 update function
To:     Thara Gopinath <thara.gopinath@linaro.org>
Cc:     linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-arm-msm@vger.kernel.org, steev@kali.org,
        sudeep.holla@arm.com, will@kernel.org, catalin.marinas@arm.com,
        linux@armlinux.org.uk, gregkh@linuxfoundation.org,
        rafael@kernel.org, viresh.kumar@linaro.org, amitk@kernel.org,
        daniel.lezcano@linaro.org, amit.kachhap@gmail.com,
        bjorn.andersson@linaro.org, agross@kernel.org
References: <20211109195714.7750-1-lukasz.luba@arm.com>
 <20211109195714.7750-5-lukasz.luba@arm.com>
 <02a848c8-a672-f3df-7144-979a9df71fcb@linaro.org>
 <911760d9-b137-5c79-d072-c2f473a3cc6a@linaro.org>
From:   Lukasz Luba <lukasz.luba@arm.com>
Message-ID: <6d667cef-3c37-7c8f-bc69-da907ac06e3f@arm.com>
Date:   Tue, 16 Nov 2021 08:28:53 +0000
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Hi Thara,

On 11/15/21 11:39 PM, Thara Gopinath wrote:
> 
> 
> On 11/15/21 3:57 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.
> 
> Also I failed to mention that, currently freq_factor is initialized as 
> cpuinfo.max_freq / 1000 which means again all the issues you mentioned 
> below can be hit, if some cpufreq driver decides to set boost at init.
> I have sent a patch earlier today to fix this.

Yes, you are right.

> 
> https://lore.kernel.org/linux-arm-msm/20211115201010.68567-1-thara.gopinath@linaro.org/T/#u 
> 
> 

Looking at the change, it makes sense. I'll try to respond to that
patch.

Thank you for looking into this issue.

Regards,
Lukasz