platform/i2c busses: pm runtime and system sleep
From: stern@rowland.harvard.edu (Alan Stern)
Date: 2011-02-18 15:05:58
Also in:
linux-i2c, lkml
On Fri, 18 Feb 2011, Rabin Vincent wrote:
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)
Yes, please find a better name! Maybe something starting with "generic_" to indicate that this applies only to devices using the GENERIC_PM_OPS.
call to the i2c and spi drivers using runtime PM.
quoted hunk ↗ jump to hunk
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. + */
This last part is normally true for all devices. If you don't want it to hold when want_interaction isn't set, you should add a good explanation to sections 6 and 7 in Documentation/power/runtime.txt.
+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.
*Don't forget that you also need to describe these things in Documentation/power/runtime.txt. Alan Stern