linux-kernel - Re: [Patch 2/2] cpufreq: tegra194: Fix unlisted boot freq warning

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Message-ID: <20201005045414.fmntm7ejad7zxcrv@vireshk-i7>
Date:   Mon, 5 Oct 2020 10:24:14 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Sumit Gupta <sumitg@...dia.com>
Cc:     rjw@...ysocki.net, thierry.reding@...il.com, jonathanh@...dia.com,
        linux-pm@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        ksitaraman@...dia.com, bbasu@...dia.com
Subject: Re: [Patch 2/2] cpufreq: tegra194: Fix unlisted boot freq warning

On 16-09-20, 22:41, Sumit Gupta wrote:
> Warning coming during boot because the boot freq set by bootloader
> gets filtered out due to big freq steps while creating freq_table.
> Fixing this by setting closest ndiv value from freq_table.
> Warning:
>   cpufreq: cpufreq_online: CPU0: Running at unlisted freq
>   cpufreq: cpufreq_online: CPU0: Unlisted initial frequency changed
> 
> Also, added change in init to wait till current frequency becomes
> equal or near to the previously requested frequency. This is done
> because it takes some time to restore the previous frequency while
> turning-on non-boot cores during exit from SC7(Suspend-to-RAM).

So you are trying to figure if the frequency is listed in freq-table or not,
otherwise setting the frequency to a value you think is appropriate. Right ?

This is what the cpufreq core already does when it printed these boot time
messages. Do we really need to add this much code in here ?

If you really don't want to see the warning, how about fixing it the way cpufreq
core does ? i.e. with this call:

ret = __cpufreq_driver_target(policy, policy->cur - 1, CPUFREQ_RELATION_L);

-- 
viresh