Commit 0140d8bd authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

PM / Domains: Automatically update overoptimistic latency information 



Measure the time of execution of the .stop(), .start(), .save_state()
and .restore_state() PM domain device callbacks and if the result
is greater than the corresponding latency value stored in the
device's struct generic_pm_domain_data object, replace the inaccurate
value with the measured time.

Do analogously for the PM domains' .power_off() and .power_off()
callbacks.

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
parent 221e9b58

drivers/base/power/domain.c

+39 −4
Original line number Diff line number Diff line
@@ -33,6 +33,20 @@ 
	__ret;							\

})



#define GENPD_DEV_TIMED_CALLBACK(genpd, type, callback, dev, field, name)	\

({										\

	ktime_t __start = ktime_get();						\

	type __retval = GENPD_DEV_CALLBACK(genpd, type, callback, dev);		\

	s64 __elapsed = ktime_to_ns(ktime_sub(ktime_get(), __start));		\

	struct generic_pm_domain_data *__gpd_data = dev_gpd_data(dev);		\

	if (__elapsed > __gpd_data->td.field) {					\

		__gpd_data->td.field = __elapsed;				\

		dev_warn(dev, name " latency exceeded, new value %lld ns\n",	\

			__elapsed);						\

	}									\

	__retval;								\

})



static LIST_HEAD(gpd_list);

static DEFINE_MUTEX(gpd_list_lock);
@@ -48,22 +62,27 @@ struct generic_pm_domain *dev_to_genpd(struct device *dev) 


static int genpd_stop_dev(struct generic_pm_domain *genpd, struct device *dev)

{

	return GENPD_DEV_CALLBACK(genpd, int, stop, dev);

	return GENPD_DEV_TIMED_CALLBACK(genpd, int, stop, dev,

					stop_latency_ns, "stop");

}



static int genpd_start_dev(struct generic_pm_domain *genpd, struct device *dev)

{

	return GENPD_DEV_CALLBACK(genpd, int, start, dev);

	return GENPD_DEV_TIMED_CALLBACK(genpd, int, start, dev,

					start_latency_ns, "start");

}



static int genpd_save_dev(struct generic_pm_domain *genpd, struct device *dev)

{

	return GENPD_DEV_CALLBACK(genpd, int, save_state, dev);

	return GENPD_DEV_TIMED_CALLBACK(genpd, int, save_state, dev,

					save_state_latency_ns, "state save");

}



static int genpd_restore_dev(struct generic_pm_domain *genpd, struct device *dev)

{

	return GENPD_DEV_CALLBACK(genpd, int, restore_state, dev);

	return GENPD_DEV_TIMED_CALLBACK(genpd, int, restore_state, dev,

					restore_state_latency_ns,

					"state restore");

}



static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd)
@@ -182,9 +201,16 @@ 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_set_active(genpd);
@@ -377,11 +403,16 @@ 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
@@ -395,6 +426,10 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd) 
			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->status = GPD_STATE_POWER_OFF;

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