On Fri, 9 Nov 2012, Lan Tianyu wrote: > This patch is to add usb port auto power off mechanism. > When usb device is suspending, usb core will send clear usb port's > POWER feature requst to power off port if all conditions were met. Actually, this is the wrong approach. What you should do, if all the conditions are met, is call pm_runtime_put(&port_dev->dev). Then the port's runtime suspend routine should be responsible for turning off the power. Similarly, whenever you want to make sure that a port is powered, you should call pm_runtime_get_sync(&port_dev->dev). Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
