Re: [PATCH v2 20/20] cpufreq: Return zero on success in boost sw setting

Viresh Kumar
2020-05-18T07:41:51Z

On 16-05-20, 15:52, Serge Semin wrote:
> On Fri, May 15, 2020 at 05:58:47PM +0200, Rafael J. Wysocki wrote:
> > > @@ -2554,7 +2554,7 @@ static int cpufreq_boost_set_sw(int state)
> > > break;
> > > }
> > > - return ret;
> > > + return ret < 0 ? ret : 0;
> > > }
> > > int cpufreq_boost_trigger_state(int state)
> >
> > IMO it is better to update the caller of this function to handle the
> > positive value possibly returned by it correctly.
>
> Could you elaborate why? Viresh seems to be ok with this solution.

And it is absolutely fine for Rafael to not agree with it :)

> As I see it the caller doesn't expect the positive value returned by the
> original freq_qos_update_request(). It just doesn't need to know whether the
> effective policy has been updated or not, it only needs to make sure the
> operations has been successful. Moreover the positive value is related only
> to the !last! active policy, which doesn't give the caller a full picture
> of the policy change anyway. So taking all of these into account I'd leave the
> fix as is.

Rafael: This function is called via a function pointer, which can call
this or a platform dependent routine (like in acpi-cpufreq.c), and it
would be reasonable IMO for the return of that callback to only look
for 0 or negative values, as is generally done in the kernel. And so
this solution looked okay to me as the positive return is coming from
the implementation detail here.

--
viresh