Re: [PATCH] devfreq_cooling: pass a pointer to devfreq in the power model callbacks

[Lukasz Luba]

Hi,

On 20/06/16 18:36, Javi Merino wrote:
> Eduardo, Rui,
>
> On Fri, Jun 03, 2016 at 10:25:31AM +0100, Javi Merino wrote:
> > When the devfreq cooling device was designed, it was an oversight not to
> > pass a pointer to the struct devfreq as the first parameters of the
> > callbacks.  The design patterns of the kernel suggest it for a good
> > reason.
> >
> > By passing a pointer to struct devfreq, the driver can register one
> > function that works with multiple devices.  With the current
> > implementation, a driver that can work with multiple devices has to
> > create multiple copies of the same function with different parameters so
> > that each devfreq_cooling_device can use the appropriate one.  By
> > passing a pointer to struct devfreq, the driver can identify which
> > device it's referring to.
> >
> > Cc: Zhang Rui <rui.zhang@xxxxxxxxx>
> > Cc: Eduardo Valentin <edubezval@xxxxxxxxx>
> > Reviewed-by: Punit Agrawal <punit.agrawal@xxxxxxx>
> > Signed-off-by: Javi Merino <javi.merino@xxxxxxx>
> > ---
> >   drivers/thermal/devfreq_cooling.c | 5 +++--
> >   include/linux/devfreq_cooling.h   | 6 ++++--
> >   2 files changed, 7 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c
> > index 01f0015f80dc..c549d83a0c7d 100644
> > --- a/drivers/thermal/devfreq_cooling.c
> > +++ b/drivers/thermal/devfreq_cooling.c
> > @@ -238,7 +238,7 @@ get_static_power(struct devfreq_cooling_device *dfc, unsigned long freq)
> >   		return 0;
> >   	}
> >
> > -	return dfc->power_ops->get_static_power(voltage);
> > +	return dfc->power_ops->get_static_power(df, voltage);
> >   }
> >
> >   /**
> > @@ -262,7 +262,8 @@ get_dynamic_power(struct devfreq_cooling_device *dfc, unsigned long freq,
> >   	struct devfreq_cooling_power *dfc_power = dfc->power_ops;
> >
> >   	if (dfc_power->get_dynamic_power)
> > -		return dfc_power->get_dynamic_power(freq, voltage);
> > +		return dfc_power->get_dynamic_power(dfc->devfreq, freq,
> > +						    voltage);
> >
> >   	freq_mhz = freq / 1000000;
> >   	power = (u64)dfc_power->dyn_power_coeff * freq_mhz * voltage * voltage;
> > diff --git a/include/linux/devfreq_cooling.h b/include/linux/devfreq_cooling.h
> > index 7adf6cc4b305..959714e93e5b 100644
> > --- a/include/linux/devfreq_cooling.h
> > +++ b/include/linux/devfreq_cooling.h
> > @@ -37,8 +37,10 @@
> >    *			@dyn_power_coeff * frequency * voltage^2
> >    */
> >   struct devfreq_cooling_power {
> > -	unsigned long (*get_static_power)(unsigned long voltage);
> > -	unsigned long (*get_dynamic_power)(unsigned long freq,
> > +	unsigned long (*get_static_power)(struct devfreq *devfreq,
> > +					  unsigned long voltage);
> > +	unsigned long (*get_dynamic_power)(struct devfreq *devfreq,
> > +					   unsigned long freq,
> >   					   unsigned long voltage);
> >   	unsigned long dyn_power_coeff;
> >   };
>
> If there are no objections, can you pick this for the next merge
> window?
>
> Thanks,
> Javi
This is very useful code, please pick it.

Reviewed-by: Lukasz Luba <lukasz.luba@xxxxxxx>

Regards,
Lukasz