Re: Re: [PATCH 6/6] PM / devfreq: Set the min_freq and max_freq of devfreq device
From: MyungJoo Ham
Date: Mon Nov 23 2015 - 02:21:08 EST
[]
> >
> > The value 0 is used for min/max_freq to declare
> > that min/max_freq is deactivated. Therefore, it is not
> > required to do so; they are not intended to show the hardware
> > configuration as well.
>
> This case consider the devfreq device using OPP because devfreq_set_freq_table()
> get the number of OPP entry in OPP list before setting the min_freq/max_freq.
> If the devfreq device don't use the OPP entry, devfreq_set_freq_table()
> will return without any operation.
>
> IMHO, when devfreq device uses the OPP table including the frequency,
> min_freq/max_freq should show the correct value as CPUFREQ framework.
>
The side effect of this patch shows up when opp_disable() and opp_enable()
are used.
For example,
1. dev->opp_disable(2GHz); /* 2GHz is the fastest and 1.6 is the second */
2. init devfreq of dev; /* setting max_freq @ 1.6G by this patch */
3. dev->opp_enable(2GHz);
4. 2GHz is still not active because max_freq is now 1.6GHz.
Cheers,
MyungJoo.