diff options
| -rw-r--r-- | drivers/base/power/domain.c | 12 | ||||
| -rw-r--r-- | drivers/base/power/domain_governor.c | 110 | ||||
| -rw-r--r-- | include/linux/pm_domain.h | 7 |
3 files changed, 129 insertions, 0 deletions
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 3af9f5a..9189619 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -398,6 +398,17 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd) } genpd->status = GPD_STATE_POWER_OFF; + genpd->power_off_time = ktime_get(); + + /* Update PM QoS information for devices in the domain. */ + list_for_each_entry_reverse(pdd, &genpd->dev_list, list_node) { + struct gpd_timing_data *td = &to_gpd_data(pdd)->td; + + pm_runtime_update_max_time_suspended(pdd->dev, + td->start_latency_ns + + td->restore_state_latency_ns + + genpd->power_on_latency_ns); + } list_for_each_entry(link, &genpd->slave_links, slave_node) { genpd_sd_counter_dec(link->master); @@ -1487,6 +1498,7 @@ void pm_genpd_init(struct generic_pm_domain *genpd, genpd->resume_count = 0; genpd->device_count = 0; genpd->suspended_count = 0; + genpd->max_off_time_ns = -1; genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend; genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume; genpd->domain.ops.runtime_idle = pm_generic_runtime_idle; diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c index 97b21c1..da78540 100644 --- a/drivers/base/power/domain_governor.c +++ b/drivers/base/power/domain_governor.c @@ -10,6 +10,7 @@ #include <linux/kernel.h> #include <linux/pm_domain.h> #include <linux/pm_qos.h> +#include <linux/hrtimer.h> /** * default_stop_ok - Default PM domain governor routine for stopping devices. @@ -28,6 +29,115 @@ bool default_stop_ok(struct device *dev) && td->break_even_ns < dev->power.max_time_suspended_ns; } +/** + * default_power_down_ok - Default generic PM domain power off governor routine. + * @pd: PM domain to check. + * + * This routine must be executed under the PM domain's lock. + */ +static bool default_power_down_ok(struct dev_pm_domain *pd) +{ + struct generic_pm_domain *genpd = pd_to_genpd(pd); + struct gpd_link *link; + struct pm_domain_data *pdd; + s64 min_dev_off_time_ns; + s64 off_on_time_ns; + ktime_t time_now = ktime_get(); + + off_on_time_ns = genpd->power_off_latency_ns + + genpd->power_on_latency_ns; + /* + * It doesn't make sense to remove power from the domain if saving + * the state of all devices in it and the power off/power on operations + * take too much time. + * + * All devices in this domain have been stopped already at this point. + */ + list_for_each_entry(pdd, &genpd->dev_list, list_node) { + if (pdd->dev->driver) + off_on_time_ns += + to_gpd_data(pdd)->td.save_state_latency_ns; + } + + /* + * Check if subdomains can be off for enough time. + * + * All subdomains have been powered off already at this point. + */ + list_for_each_entry(link, &genpd->master_links, master_node) { + struct generic_pm_domain *sd = link->slave; + s64 sd_max_off_ns = sd->max_off_time_ns; + + if (sd_max_off_ns < 0) + continue; + + sd_max_off_ns -= ktime_to_ns(ktime_sub(time_now, + sd->power_off_time)); + /* + * Check if the subdomain is allowed to be off long enough for + * the current domain to turn off and on (that's how much time + * it will have to wait worst case). + */ + if (sd_max_off_ns <= off_on_time_ns) + return false; + } + + /* + * Check if the devices in the domain can be off enough time. + */ + min_dev_off_time_ns = -1; + list_for_each_entry(pdd, &genpd->dev_list, list_node) { + struct gpd_timing_data *td; + struct device *dev = pdd->dev; + s64 dev_off_time_ns; + + if (!dev->driver || dev->power.max_time_suspended_ns < 0) + continue; + + td = &to_gpd_data(pdd)->td; + dev_off_time_ns = dev->power.max_time_suspended_ns - + (td->start_latency_ns + td->restore_state_latency_ns + + ktime_to_ns(ktime_sub(time_now, + dev->power.suspend_time))); + if (dev_off_time_ns <= off_on_time_ns) + return false; + + if (min_dev_off_time_ns > dev_off_time_ns + || min_dev_off_time_ns < 0) + min_dev_off_time_ns = dev_off_time_ns; + } + + if (min_dev_off_time_ns < 0) { + /* + * There are no latency constraints, so the domain can spend + * arbitrary time in the "off" state. + */ + genpd->max_off_time_ns = -1; + return true; + } + + /* + * The difference between the computed minimum delta and the time needed + * to turn the domain on is the maximum theoretical time this domain can + * spend in the "off" state. + */ + min_dev_off_time_ns -= genpd->power_on_latency_ns; + + /* + * If the difference between the computed minimum delta and the time + * needed to turn the domain off and back on on is smaller than the + * domain's power break even time, removing power from the domain is not + * worth it. + */ + if (genpd->break_even_ns > + min_dev_off_time_ns - genpd->power_off_latency_ns) + return false; + + genpd->max_off_time_ns = min_dev_off_time_ns; + return true; +} + struct dev_power_governor simple_qos_governor = { .stop_ok = default_stop_ok, + .power_down_ok = default_power_down_ok, }; diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index f6745c2..cc1a245 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -61,8 +61,13 @@ struct generic_pm_domain { bool suspend_power_off; /* Power status before system suspend */ bool dev_irq_safe; /* Device callbacks are IRQ-safe */ int (*power_off)(struct generic_pm_domain *domain); + s64 power_off_latency_ns; int (*power_on)(struct generic_pm_domain *domain); + s64 power_on_latency_ns; struct gpd_dev_ops dev_ops; + s64 break_even_ns; /* Power break even for the entire domain. */ + s64 max_off_time_ns; /* Maximum allowed "suspended" time. */ + ktime_t power_off_time; }; static inline struct generic_pm_domain *pd_to_genpd(struct dev_pm_domain *pd) @@ -80,6 +85,8 @@ struct gpd_link { struct gpd_timing_data { s64 stop_latency_ns; s64 start_latency_ns; + s64 save_state_latency_ns; + s64 restore_state_latency_ns; s64 break_even_ns; }; |
