This is a little rework of linux power scheme. TODO: - remove recursive call - control cast on 64 bit architecture - semply code
I would like to know your opinion. not-really-signed-off-by: Michael Trimarchi <[email protected]> --- diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 3098c46..2a6ddb3 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -63,6 +63,40 @@ void device_pm_unlock(void) mutex_unlock(&dpm_list_mtx); } +int device_set_may_suspend_enable(struct device *dev, void *data) +{ + /* if the device is suspend the subtree is in may_suspend status */ + if (!dev->power.can_suspend) + goto out; + + dev->power.may_suspend = (unsigned int)data; + device_for_each_child(dev, data, + device_set_may_suspend_enable); +out: + return 0; +} + +/** + * device_set_suspend_enable - enable/disable device to suspend + */ +int device_set_suspend_enable(struct device *dev, int enable) +{ + mutex_lock(&dpm_list_mtx); + + if (dev->power.can_suspend == !!enable) + goto out; + + /* Update device children to avoid suspend */ + device_for_each_child(dev, (void *)!!enable, + device_set_may_suspend_enable); + + dev->power.can_suspend = !!enable; +out: + mutex_unlock(&dpm_list_mtx); + return 0; +} +EXPORT_SYMBOL_GPL(device_set_suspend_enable); + /** * device_pm_add - add a device to the list of active devices * @dev: Device to be added to the list @@ -77,6 +111,13 @@ void device_pm_add(struct device *dev) if (dev->parent->power.status >= DPM_SUSPENDING) dev_warn(dev, "parent %s should not be sleeping\n", dev_name(dev->parent)); + if (!device_can_suspend(dev->parent)) { + mutex_unlock(&dpm_list_mtx); + /* if the parent has suspend disable, propagate it + * to the new child */ + device_set_may_suspend_enable(dev, 0); + mutex_lock(&dpm_list_mtx); + } } else if (transition_started) { /* * We refuse to register parentless devices while a PM @@ -120,13 +161,13 @@ static int pm_op(struct device *dev, struct dev_pm_ops *ops, switch (state.event) { #ifdef CONFIG_SUSPEND case PM_EVENT_SUSPEND: - if (ops->suspend) { + if (device_can_suspend(dev) && ops->suspend) { error = ops->suspend(dev); suspend_report_result(ops->suspend, error); } break; case PM_EVENT_RESUME: - if (ops->resume) { + if (device_can_suspend(dev) && ops->resume) { error = ops->resume(dev); suspend_report_result(ops->resume, error); } diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h index 41f51fa..1197b13 100644 --- a/drivers/base/power/power.h +++ b/drivers/base/power/power.h @@ -1,6 +1,13 @@ static inline void device_pm_init(struct device *dev) { dev->power.status = DPM_ON; + dev->power.can_suspend = 1; + dev->power.may_suspend = 1; +} + +static inline int device_can_suspend(struct device *dev) +{ + return (dev->power.can_suspend && dev->power.may_suspend); } #ifdef CONFIG_PM_SLEEP diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c index 596aeec..25236aa 100644 --- a/drivers/base/power/sysfs.c +++ b/drivers/base/power/sysfs.c @@ -43,6 +43,34 @@ static const char enabled[] = "enabled"; static const char disabled[] = "disabled"; +static ssize_t suspend_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%s\n", device_can_suspend(dev) + ? enabled : disabled); +} + +static ssize_t +suspend_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t n) +{ + char *cp; + int len = n; + + cp = memchr(buf, '\n', n); + if (cp) + len = cp - buf; + if (len == sizeof enabled - 1 + && strncmp(buf, enabled, sizeof enabled - 1) == 0) + device_set_suspend_enable(dev, 1); + else if (len == sizeof disabled - 1 + && strncmp(buf, disabled, sizeof disabled - 1) == 0) + device_set_suspend_enable(dev, 0); + else + return -EINVAL; + return n; +} + static ssize_t wake_show(struct device * dev, struct device_attribute *attr, char * buf) { @@ -76,10 +104,11 @@ wake_store(struct device * dev, struct device_attribute *attr, } static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store); - +static DEVICE_ATTR(suspend, 0644, suspend_show, suspend_store); static struct attribute * power_attrs[] = { &dev_attr_wakeup.attr, + &dev_attr_suspend.attr, NULL, }; static struct attribute_group pm_attr_group = { diff --git a/include/linux/device.h b/include/linux/device.h index fdb073b..dc9f242 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -487,6 +487,7 @@ extern struct device *device_find_child(struct device *dev, void *data, int (*match)(struct device *dev, void *data)); extern int device_rename(struct device *dev, char *new_name); extern int device_move(struct device *dev, struct device *new_parent); +extern int device_set_suspend_enable(struct device *dev, int enable); /* * Root device objects for grouping under /sys/devices diff --git a/include/linux/pm.h b/include/linux/pm.h index de2e0a8..7586a90 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -319,6 +319,9 @@ struct dev_pm_info { pm_message_t power_state; unsigned can_wakeup:1; unsigned should_wakeup:1; + unsigned can_suspend:1; + unsigned may_suspend:1; + enum dpm_state status; /* Owned by the PM core */ #ifdef CONFIG_PM_SLEEP struct list_head entry;
