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

From: Lukasz Luba
Date: Tue Nov 16 2021 - 03:29:06 EST

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.

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

Thank you for looking into this issue.