diff options
Diffstat (limited to 'drivers/base/power/domain_governor.c')
| -rw-r--r-- | drivers/base/power/domain_governor.c | 45 |
1 files changed, 42 insertions, 3 deletions
diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c index 2aae623fd84..3a5c5346bc4 100644 --- a/drivers/base/power/domain_governor.c +++ b/drivers/base/power/domain_governor.c @@ -46,18 +46,34 @@ static int dev_update_qos_constraint(struct device *dev, void *data) bool default_stop_ok(struct device *dev) { struct gpd_timing_data *td = &dev_gpd_data(dev)->td; + unsigned long flags; s64 constraint_ns; dev_dbg(dev, "%s()\n", __func__); - constraint_ns = dev_pm_qos_read_value(dev); + spin_lock_irqsave(&dev->power.lock, flags); + + if (!td->constraint_changed) { + bool ret = td->cached_stop_ok; + + spin_unlock_irqrestore(&dev->power.lock, flags); + return ret; + } + td->constraint_changed = false; + td->cached_stop_ok = false; + td->effective_constraint_ns = -1; + constraint_ns = __dev_pm_qos_read_value(dev); + + spin_unlock_irqrestore(&dev->power.lock, flags); + if (constraint_ns < 0) return false; constraint_ns *= NSEC_PER_USEC; /* * We can walk the children without any additional locking, because - * they all have been suspended at this point. + * they all have been suspended at this point and their + * effective_constraint_ns fields won't be modified in parallel with us. */ if (!dev->power.ignore_children) device_for_each_child(dev, &constraint_ns, @@ -69,11 +85,13 @@ bool default_stop_ok(struct device *dev) return false; } td->effective_constraint_ns = constraint_ns; + td->cached_stop_ok = constraint_ns > td->stop_latency_ns || + constraint_ns == 0; /* * The children have been suspended already, so we don't need to take * their stop latencies into account here. */ - return constraint_ns > td->stop_latency_ns || constraint_ns == 0; + return td->cached_stop_ok; } /** @@ -90,6 +108,25 @@ static bool default_power_down_ok(struct dev_pm_domain *pd) s64 min_dev_off_time_ns; s64 off_on_time_ns; + if (genpd->max_off_time_changed) { + struct gpd_link *link; + + /* + * We have to invalidate the cached results for the masters, so + * use the observation that default_power_down_ok() is not + * going to be called for any master until this instance + * returns. + */ + list_for_each_entry(link, &genpd->slave_links, slave_node) + link->master->max_off_time_changed = true; + + genpd->max_off_time_changed = false; + genpd->cached_power_down_ok = false; + genpd->max_off_time_ns = -1; + } else { + return genpd->cached_power_down_ok; + } + off_on_time_ns = genpd->power_off_latency_ns + genpd->power_on_latency_ns; /* @@ -165,6 +202,8 @@ static bool default_power_down_ok(struct dev_pm_domain *pd) min_dev_off_time_ns = constraint_ns; } + genpd->cached_power_down_ok = true; + /* * If the computed minimum device off time is negative, there are no * latency constraints, so the domain can spend arbitrary time in the |