Re: [PATCH] PM / Domains: Extract code to power off/on a PM domain

[Rafael J. Wysocki]

On Thursday, November 13, 2014 03:10:07 PM Pavel Machek wrote:
> On Mon 2014-11-10 19:39:19, Geert Uytterhoeven wrote:
> > PM domains are powered on/off from various places. Some callers do
> > latency measurements, others don't. Consolidate using two helper
> > functions, which always measure the latencies, and update the stored
> > latencies when needed.
> > 
> > Other minor changes:
> >   - Use pr_warn() instead of pr_warning(),
> >   - There's no need to check genpd->name, %s handles NULL pointers fine,
> >   - Make the warning format strings identical, to save memory.
> > 
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> > Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> > Reviewed-by: Kevin Hilman <khilman@xxxxxxxxxx>
> 
> Acked-by: Pavel Machek <pavel@xxxxxx>

Patch queued up for 3.19, thanks!

> > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> > index a841bab441147b3d..2fccf2c2575e4fa3 100644
> > --- a/drivers/base/power/domain.c
> > +++ b/drivers/base/power/domain.c
> > @@ -151,6 +151,59 @@ static void genpd_recalc_cpu_exit_latency(struct generic_pm_domain *genpd)
> >  	genpd->cpuidle_data->idle_state->exit_latency = usecs64;
> >  }
> >  
> > +static int genpd_power_on(struct generic_pm_domain *genpd)
> > +{
> > +	ktime_t time_start;
> > +	s64 elapsed_ns;
> > +	int ret;
> > +
> > +	if (!genpd->power_on)
> > +		return 0;
> > +
> > +	time_start = ktime_get();
> > +	ret = genpd->power_on(genpd);
> > +	if (ret)
> > +		return ret;
> > +
> > +	elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
> > +	if (elapsed_ns <= genpd->power_on_latency_ns)
> > +		return ret;
> > +
> > +	genpd->power_on_latency_ns = elapsed_ns;
> > +	genpd->max_off_time_changed = true;
> > +	genpd_recalc_cpu_exit_latency(genpd);
> > +	pr_warn("%s: Power-%s latency exceeded, new value %lld ns\n",
> > +		genpd->name, "on", elapsed_ns);
> > +
> > +	return ret;
> > +}
> > +
> > +static int genpd_power_off(struct generic_pm_domain *genpd)
> > +{
> > +	ktime_t time_start;
> > +	s64 elapsed_ns;
> > +	int ret;
> > +
> > +	if (!genpd->power_off)
> > +		return 0;
> > +
> > +	time_start = ktime_get();
> > +	ret = genpd->power_off(genpd);
> > +	if (ret == -EBUSY)
> > +		return ret;
> > +
> > +	elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
> > +	if (elapsed_ns <= genpd->power_off_latency_ns)
> > +		return ret;
> > +
> > +	genpd->power_off_latency_ns = elapsed_ns;
> > +	genpd->max_off_time_changed = true;
> > +	pr_warn("%s: Power-%s latency exceeded, new value %lld ns\n",
> > +		genpd->name, "off", elapsed_ns);
> > +
> > +	return ret;
> > +}
> > +
> >  /**
> >   * __pm_genpd_poweron - Restore power to a given PM domain and its masters.
> >   * @genpd: PM domain to power up.
> > @@ -222,25 +275,9 @@ static int __pm_genpd_poweron(struct generic_pm_domain *genpd)
> >  		}
> >  	}
> >  
> > -	if (genpd->power_on) {
> > -		ktime_t time_start = ktime_get();
> > -		s64 elapsed_ns;
> > -
> > -		ret = genpd->power_on(genpd);
> > -		if (ret)
> > -			goto err;
> > -
> > -		elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
> > -		if (elapsed_ns > genpd->power_on_latency_ns) {
> > -			genpd->power_on_latency_ns = elapsed_ns;
> > -			genpd->max_off_time_changed = true;
> > -			genpd_recalc_cpu_exit_latency(genpd);
> > -			if (genpd->name)
> > -				pr_warning("%s: Power-on latency exceeded, "
> > -					"new value %lld ns\n", genpd->name,
> > -					elapsed_ns);
> > -		}
> > -	}
> > +	ret = genpd_power_on(genpd);
> > +	if (ret)
> > +		goto err;
> >  
> >   out:
> >  	genpd_set_active(genpd);
> > @@ -529,16 +566,11 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
> >  	}
> >  
> >  	if (genpd->power_off) {
> > -		ktime_t time_start;
> > -		s64 elapsed_ns;
> > -
> >  		if (atomic_read(&genpd->sd_count) > 0) {
> >  			ret = -EBUSY;
> >  			goto out;
> >  		}
> >  
> > -		time_start = ktime_get();
> > -
> >  		/*
> >  		 * If sd_count > 0 at this point, one of the subdomains hasn't
> >  		 * managed to call pm_genpd_poweron() for the master yet after
> > @@ -547,21 +579,11 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
> >  		 * the pm_genpd_poweron() restore power for us (this shouldn't
> >  		 * happen very often).
> >  		 */
> > -		ret = genpd->power_off(genpd);
> > +		ret = genpd_power_off(genpd);
> >  		if (ret == -EBUSY) {
> >  			genpd_set_active(genpd);
> >  			goto out;
> >  		}
> > -
> > -		elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
> > -		if (elapsed_ns > genpd->power_off_latency_ns) {
> > -			genpd->power_off_latency_ns = elapsed_ns;
> > -			genpd->max_off_time_changed = true;
> > -			if (genpd->name)
> > -				pr_warning("%s: Power-off latency exceeded, "
> > -					"new value %lld ns\n", genpd->name,
> > -					elapsed_ns);
> > -		}
> >  	}
> >  
> >  	genpd->status = GPD_STATE_POWER_OFF;
> > @@ -796,8 +818,7 @@ static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd)
> >  	    || atomic_read(&genpd->sd_count) > 0)
> >  		return;
> >  
> > -	if (genpd->power_off)
> > -		genpd->power_off(genpd);
> > +	genpd_power_off(genpd);
> >  
> >  	genpd->status = GPD_STATE_POWER_OFF;
> >  
> > @@ -828,8 +849,7 @@ static void pm_genpd_sync_poweron(struct generic_pm_domain *genpd)
> >  		genpd_sd_counter_inc(link->master);
> >  	}
> >  
> > -	if (genpd->power_on)
> > -		genpd->power_on(genpd);
> > +	genpd_power_on(genpd);
> >  
> >  	genpd->status = GPD_STATE_ACTIVE;
> >  }
> > @@ -1251,8 +1271,7 @@ static int pm_genpd_restore_noirq(struct device *dev)
> >  			 * If the domain was off before the hibernation, make
> >  			 * sure it will be off going forward.
> >  			 */
> > -			if (genpd->power_off)
> > -				genpd->power_off(genpd);
> > +			genpd_power_off(genpd);
> >  
> >  			return 0;
> >  		}
> 
> 

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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