diff options
| -rw-r--r-- | drivers/base/power/domain.c | 144 | ||||
| -rw-r--r-- | include/linux/pm_domain.h | 3 |
2 files changed, 102 insertions, 45 deletions
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index d06f3bb..7e6cc8a 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -44,7 +44,8 @@ static void genpd_acquire_lock(struct generic_pm_domain *genpd) for (;;) { prepare_to_wait(&genpd->status_wait_queue, &wait, TASK_UNINTERRUPTIBLE); - if (genpd->status != GPD_STATE_BUSY) + if (genpd->status == GPD_STATE_ACTIVE + || genpd->status == GPD_STATE_POWER_OFF) break; mutex_unlock(&genpd->lock); @@ -60,6 +61,12 @@ static void genpd_release_lock(struct generic_pm_domain *genpd) mutex_unlock(&genpd->lock); } +static void genpd_set_active(struct generic_pm_domain *genpd) +{ + if (genpd->resume_count == 0) + genpd->status = GPD_STATE_ACTIVE; +} + /** * pm_genpd_poweron - Restore power to a given PM domain and its parents. * @genpd: PM domain to power up. @@ -75,42 +82,24 @@ int pm_genpd_poweron(struct generic_pm_domain *genpd) start: if (parent) { - mutex_lock(&parent->lock); + genpd_acquire_lock(parent); mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING); } else { mutex_lock(&genpd->lock); } - /* - * Wait for the domain to transition into either the active, - * or the power off state. - */ - for (;;) { - prepare_to_wait(&genpd->status_wait_queue, &wait, - TASK_UNINTERRUPTIBLE); - if (genpd->status != GPD_STATE_BUSY) - break; - mutex_unlock(&genpd->lock); - if (parent) - mutex_unlock(&parent->lock); - - schedule(); - - if (parent) { - mutex_lock(&parent->lock); - mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING); - } else { - mutex_lock(&genpd->lock); - } - } - finish_wait(&genpd->status_wait_queue, &wait); if (genpd->status == GPD_STATE_ACTIVE || (genpd->prepared_count > 0 && genpd->suspend_power_off)) goto out; + if (genpd->status != GPD_STATE_POWER_OFF) { + genpd_set_active(genpd); + goto out; + } + if (parent && parent->status != GPD_STATE_ACTIVE) { mutex_unlock(&genpd->lock); - mutex_unlock(&parent->lock); + genpd_release_lock(parent); ret = pm_genpd_poweron(parent); if (ret) @@ -125,14 +114,14 @@ int pm_genpd_poweron(struct generic_pm_domain *genpd) goto out; } - genpd->status = GPD_STATE_ACTIVE; + genpd_set_active(genpd); if (parent) parent->sd_count++; out: mutex_unlock(&genpd->lock); if (parent) - mutex_unlock(&parent->lock); + genpd_release_lock(parent); return ret; } @@ -210,6 +199,20 @@ static void __pm_genpd_restore_device(struct dev_list_entry *dle, } /** + * genpd_abort_poweroff - Check if a PM domain power off should be aborted. + * @genpd: PM domain to check. + * + * Return true if a PM domain's status changed to GPD_STATE_ACTIVE during + * a "power off" operation, which means that a "power on" has occured in the + * meantime, or if its resume_count field is different from zero, which means + * that one of its devices has been resumed in the meantime. + */ +static bool genpd_abort_poweroff(struct generic_pm_domain *genpd) +{ + return genpd->status == GPD_STATE_ACTIVE || genpd->resume_count > 0; +} + +/** * pm_genpd_poweroff - Remove power from a given PM domain. * @genpd: PM domain to power down. * @@ -223,9 +226,17 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd) struct generic_pm_domain *parent; struct dev_list_entry *dle; unsigned int not_suspended; - int ret; + int ret = 0; - if (genpd->status == GPD_STATE_POWER_OFF || genpd->prepared_count > 0) + start: + /* + * Do not try to power off the domain in the following situations: + * (1) The domain is already in the "power off" state. + * (2) System suspend is in progress. + * (3) One of the domain's devices is being resumed right now. + */ + if (genpd->status == GPD_STATE_POWER_OFF || genpd->prepared_count > 0 + || genpd->resume_count > 0) return 0; if (genpd->sd_count > 0) @@ -239,34 +250,54 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd) if (not_suspended > genpd->in_progress) return -EBUSY; + if (genpd->poweroff_task) { + /* + * Another instance of pm_genpd_poweroff() is executing + * callbacks, so tell it to start over and return. + */ + genpd->status = GPD_STATE_REPEAT; + return 0; + } + if (genpd->gov && genpd->gov->power_down_ok) { if (!genpd->gov->power_down_ok(&genpd->domain)) return -EAGAIN; } genpd->status = GPD_STATE_BUSY; + genpd->poweroff_task = current; list_for_each_entry_reverse(dle, &genpd->dev_list, node) { ret = __pm_genpd_save_device(dle, genpd); if (ret) goto err_dev; - } - mutex_unlock(&genpd->lock); + if (genpd_abort_poweroff(genpd)) + goto out; + + if (genpd->status == GPD_STATE_REPEAT) { + genpd->poweroff_task = NULL; + goto start; + } + } parent = genpd->parent; if (parent) { + mutex_unlock(&genpd->lock); + genpd_acquire_lock(parent); mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING); - } else { - mutex_lock(&genpd->lock); + + if (genpd_abort_poweroff(genpd)) { + genpd_release_lock(parent); + goto out; + } } if (genpd->power_off) genpd->power_off(genpd); genpd->status = GPD_STATE_POWER_OFF; - wake_up_all(&genpd->status_wait_queue); if (parent) { genpd_sd_counter_dec(parent); @@ -276,16 +307,17 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd) genpd_release_lock(parent); } - return 0; + out: + genpd->poweroff_task = NULL; + wake_up_all(&genpd->status_wait_queue); + return ret; err_dev: list_for_each_entry_continue(dle, &genpd->dev_list, node) __pm_genpd_restore_device(dle, genpd); - genpd->status = GPD_STATE_ACTIVE; - wake_up_all(&genpd->status_wait_queue); - - return ret; + genpd_set_active(genpd); + goto out; } /** @@ -327,11 +359,11 @@ static int pm_genpd_runtime_suspend(struct device *dev) return ret; } - genpd_acquire_lock(genpd); + mutex_lock(&genpd->lock); genpd->in_progress++; pm_genpd_poweroff(genpd); genpd->in_progress--; - genpd_release_lock(genpd); + mutex_unlock(&genpd->lock); return 0; } @@ -365,6 +397,7 @@ static void __pm_genpd_runtime_resume(struct device *dev, static int pm_genpd_runtime_resume(struct device *dev) { struct generic_pm_domain *genpd; + DEFINE_WAIT(wait); int ret; dev_dbg(dev, "%s()\n", __func__); @@ -377,12 +410,31 @@ static int pm_genpd_runtime_resume(struct device *dev) if (ret) return ret; - genpd_acquire_lock(genpd); + mutex_lock(&genpd->lock); genpd->status = GPD_STATE_BUSY; + genpd->resume_count++; + for (;;) { + prepare_to_wait(&genpd->status_wait_queue, &wait, + TASK_UNINTERRUPTIBLE); + /* + * If current is the powering off task, we have been called + * reentrantly from one of the device callbacks, so we should + * not wait. + */ + if (!genpd->poweroff_task || genpd->poweroff_task == current) + break; + mutex_unlock(&genpd->lock); + + schedule(); + + mutex_lock(&genpd->lock); + } + finish_wait(&genpd->status_wait_queue, &wait); __pm_genpd_runtime_resume(dev, genpd); - genpd->status = GPD_STATE_ACTIVE; + genpd->resume_count--; + genpd_set_active(genpd); wake_up_all(&genpd->status_wait_queue); - genpd_release_lock(genpd); + mutex_unlock(&genpd->lock); if (genpd->start_device) genpd->start_device(dev); @@ -1130,6 +1182,8 @@ void pm_genpd_init(struct generic_pm_domain *genpd, genpd->sd_count = 0; genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE; init_waitqueue_head(&genpd->status_wait_queue); + genpd->poweroff_task = NULL; + genpd->resume_count = 0; genpd->device_count = 0; genpd->suspended_count = 0; genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend; diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index c71457c..feb80af 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -14,6 +14,7 @@ enum gpd_status { GPD_STATE_ACTIVE = 0, /* PM domain is active */ GPD_STATE_BUSY, /* Something is happening to the PM domain */ + GPD_STATE_REPEAT, /* Power off in progress, to be repeated */ GPD_STATE_POWER_OFF, /* PM domain is off */ }; @@ -34,6 +35,8 @@ struct generic_pm_domain { unsigned int sd_count; /* Number of subdomains with power "on" */ enum gpd_status status; /* Current state of the domain */ wait_queue_head_t status_wait_queue; + struct task_struct *poweroff_task; /* Powering off task */ + unsigned int resume_count; /* Number of devices being resumed */ unsigned int device_count; /* Number of devices */ unsigned int suspended_count; /* System suspend device counter */ unsigned int prepared_count; /* Suspend counter of prepared devices */ |
