platform/i2c busses: pm runtime and system sleep
From: Rabin Vincent <hidden>
Date: 2011-02-18 02:49:33
Also in:
linux-i2c, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, hibernation (aka software suspend, aka swsusp), power management core, suspend to ram, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds
On Thu, Feb 17, 2011 at 20:55, Rabin Vincent [off-list ref] wrote:
This will solve the platform vs AMBA bus, but shouldn't we really be aiming for consistent behaviour between these and the other busses such as I2C and SPI, which are also usually commonly used on the same platforms and are using GENERIC_PM_OPS? Should we be auditing all platform drivers and then switch platform to the GENERIC_PM_OPS? Or should the two points (1) and (2) be not handled in the bus at all and be left to individual drivers (in which case we should audit i2c and spi and change GENERIC_PM_OPS)?
How about something like the below? If we have something like this, we can just switch platform to GENERIC_PM_OPS and add the pm_runtime_want_interaction() (or something better named) call to the i2c and spi drivers using runtime PM.
diff --git a/drivers/base/power/generic_ops.c b/drivers/base/power/generic_ops.c
index 42f97f9..c2a3b63 100644
--- a/drivers/base/power/generic_ops.c
+++ b/drivers/base/power/generic_ops.c@@ -87,7 +87,10 @@ static int __pm_generic_call(struct device *dev, int event) const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; int (*callback)(struct device *); - if (!pm || pm_runtime_suspended(dev)) + if (!pm) + return 0; + + if (device_want_interaction(dev) && pm_runtime_suspended(dev)) return 0; switch (event) {
@@ -185,7 +188,7 @@ static int __pm_generic_resume(struct device *dev,int event)
return 0;
ret = callback(dev);
- if (!ret && pm_runtime_enabled(dev)) {
+ if (!ret && device_want_interaction(dev) && pm_runtime_enabled(dev)) {
pm_runtime_disable(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 42615b4..2b8a099 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c@@ -1069,6 +1069,30 @@ void pm_runtime_allow(struct device *dev) EXPORT_SYMBOL_GPL(pm_runtime_allow); /** + * pm_runtime_want_interaction - Enable interaction between system sleep + * and runtime PM callbacks at the bus/subsystem + * level. + * @dev: Device to handle + * + * Set the power.want_interaction flage, which tells the generic PM subsystem + * ops that the following actions should be done during system suspend/resume: + * + * - If the device has been runtime suspended, the driver's + * suspend() handler will not be invoked. + * + * - If the device has a resume() pm callback, and the resume() + * callback returns success on system resume, the device's + * runtime PM status will be set to active. + */ +void pm_runtime_want_interaction(struct device *dev) +{ + spin_lock_irq(&dev->power.lock); + dev->power.want_interaction = 1; + spin_unlock_irq(&dev->power.lock); +} +EXPORT_SYMBOL_GPL(pm_runtime_want_interaction); + +/** * pm_runtime_no_callbacks - Ignore run-time PM callbacks for a device. * @dev: Device to handle. *
diff --git a/include/linux/pm.h b/include/linux/pm.h
index dd9c7ab..b9bcfb9 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h@@ -450,6 +450,7 @@ struct dev_pm_info { unsigned int irq_safe:1; unsigned int use_autosuspend:1; unsigned int timer_autosuspends:1; + unsigned int want_interaction:1; enum rpm_request request; enum rpm_status runtime_status; int runtime_error;
diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index d34f067..a0e081b 100644
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h@@ -44,6 +44,7 @@ extern void pm_runtime_irq_safe(struct device *dev); extern void __pm_runtime_use_autosuspend(struct device *dev, bool use); extern void pm_runtime_set_autosuspend_delay(struct device *dev, int delay); extern unsigned long pm_runtime_autosuspend_expiration(struct device *dev); +static void pm_runtime_want_system_sleep_interaction(struct device *dev); static inline bool pm_children_suspended(struct device *dev) {
@@ -66,6 +67,11 @@ static inline void pm_runtime_put_noidle(struct device *dev) atomic_add_unless(&dev->power.usage_count, -1, 0); } +static inline bool device_want_interaction(struct device *dev) +{ + return dev->power.want_interaction; +} + static inline bool device_run_wake(struct device *dev) { return dev->power.run_wake;
@@ -122,6 +128,7 @@ static inline bool pm_children_suspended(structdevice *dev) { return false; }
static inline void pm_suspend_ignore_children(struct device *dev, bool en) {}
static inline void pm_runtime_get_noresume(struct device *dev) {}
static inline void pm_runtime_put_noidle(struct device *dev) {}
+static inline bool device_want_interaction(struct device *dev) {
return false; }
static inline bool device_run_wake(struct device *dev) { return false; }
static inline void device_set_run_wake(struct device *dev, bool enable) {}
static inline bool pm_runtime_suspended(struct device *dev) { return false; }@@ -132,6 +139,7 @@ static inline intpm_generic_runtime_suspend(struct device *dev) { return 0; }
static inline int pm_generic_runtime_resume(struct device *dev) { return 0; }
static inline void pm_runtime_no_callbacks(struct device *dev) {}
static inline void pm_runtime_irq_safe(struct device *dev) {}
+static inline void pm_runtime_want_system_sleep_interaction(struct
device *dev) {}
static inline void pm_runtime_mark_last_busy(struct device *dev) {}
static inline void __pm_runtime_use_autosuspend(struct device *dev,