Re: [PATCH v2] thermal: re-calculate k_po/k_pu when update sustainable power

[Leo Yan <leo.yan@linaro.org>]

Hi Eduardo,

Thanks for review.

On Thu, Dec 31, 2015 at 09:21:26AM -0800, Eduardo Valentin wrote:
> On Wed, Dec 30, 2015 at 06:38:40PM +0800, Leo Yan wrote:
> > k_po/k_pu are in essence ratio values compared with sustainable power.
> > So when update sustainable power, we can recalculate k_po/k_pu simply
> > with below formula:
> > 
> >                sustainable_power(new)
> >     k_p(new) = ---------------------- * k_p(old)
> >                sustainable_power(old)
> > 
> > Signed-off-by: Leo Yan <leo.yan@linaro.org>
> > ---
> >  drivers/thermal/thermal_core.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> > index d9e525c..223f8df 100644
> > --- a/drivers/thermal/thermal_core.c
> > +++ b/drivers/thermal/thermal_core.c
> > @@ -908,7 +908,7 @@ sustainable_power_store(struct device *dev, struct device_attribute *devattr,
> >  			const char *buf, size_t count)
> >  {
> >  	struct thermal_zone_device *tz = to_thermal_zone(dev);
> > -	u32 sustainable_power;
> > +	u32 sustainable_power, old_val;
> >  
> >  	if (!tz->tzp)
> >  		return -EIO;
> > @@ -916,8 +916,12 @@ sustainable_power_store(struct device *dev, struct device_attribute *devattr,
> >  	if (kstrtou32(buf, 10, &sustainable_power))
> >  		return -EINVAL;
> >  
> > +	old_val = tz->tzp->sustainable_power;
> > +
> >  	tz->tzp->sustainable_power = sustainable_power;
> >  
> > +	tz->tzp->k_po = (tz->tzp->k_po * sustainable_power) / old_val;
> > +	tz->tzp->k_pu = (tz->tzp->k_pu * sustainable_power) / old_val;
> 
> I believe this has to be done by the governor. These properties are
> power_allocator specific. thermal_core should not really care about
> them.

Okay, I will try to update these properties in power_allocator.c.
Javi, do you think this is fine for you?

Thanks,
Leo Yan

> 
> >  	return count;
> >  }
> >  static DEVICE_ATTR(sustainable_power, S_IWUSR | S_IRUGO, sustainable_power_show,
> > -- 
> > 1.9.1
> >