On 13/07/2020 04:25, Viresh Kumar wrote:
> On 12-07-20, 11:06, Jon Hunter wrote:
>> Commit 6cc3d0e9a097 ("cpufreq: tegra186: add
>> CPUFREQ_NEED_INITIAL_FREQ_CHECK flag") fixed CPUFREQ support for
>> Tegra186 but as a consequence the following warnings are now seen on
>> boot ...
>>
>> cpufreq: cpufreq_online: CPU0: Running at unlisted freq: 0 KHz
>> cpufreq: cpufreq_online: CPU0: Unlisted initial frequency changed to: 2035200 KHz
>> cpufreq: cpufreq_online: CPU1: Running at unlisted freq: 0 KHz
>> cpufreq: cpufreq_online: CPU1: Unlisted initial frequency changed to: 2035200 KHz
>> cpufreq: cpufreq_online: CPU2: Running at unlisted freq: 0 KHz
>> cpufreq: cpufreq_online: CPU2: Unlisted initial frequency changed to: 2035200 KHz
>> cpufreq: cpufreq_online: CPU3: Running at unlisted freq: 0 KHz
>> cpufreq: cpufreq_online: CPU3: Unlisted initial frequency changed to: 2035200 KHz
>> cpufreq: cpufreq_online: CPU4: Running at unlisted freq: 0 KHz
>> cpufreq: cpufreq_online: CPU4: Unlisted initial frequency changed to: 2035200 KHz
>> cpufreq: cpufreq_online: CPU5: Running at unlisted freq: 0 KHz
>> cpufreq: cpufreq_online: CPU5: Unlisted initial frequency changed to: 2035200 KHz
>>
>> Although we could fix this by adding a 'get' operator for the Tegra186
>> CPUFREQ driver, there is really little point because the CPUFREQ on
>> Tegra186 is set by writing a value stored in the frequency table to a
>> register and we just need to set the initial frequency.
>
> The hardware still runs at the frequency requested by cpufreq core here, right ?
Yes.
> It is better to provide the get() callback as it is also used to show the
> current frequency in userspace.
I looked at that and I saw that if the get() callback is not provided,
the current frequency showed by userspace is policy->cur. For this
device, policy->cur is accurate and so if we added the get() callback we
essentially just going to return policy->cur. Therefore, given that we
already know policy->cur, I did not see the point in adding a device
specific handler to do the same thing.
Cheers
Jon
--
nvpublic
