Am Donnerstag, 3. Juni 2010 08:33:02 schrieb Radha Mohan: > Hi all, > > I was trying to understand power management in USB and found that the > usb_port_suspend() and usb_port_resume() functions are not being used > by any drivers apart from a generic driver. These functions will do > suspend and resume on the device. My doubt is why these functions are > not exported. If anyone wants to develop a driver and wishes to use > these functions then it won't be possible. Why is this limitation? Drivers are for interfaces. Interfaces cannot be suspended independently. Therefore reference counting is used. So if a) the counters for all interfaces hit zero b) suspension is enabled through sysfs the generic code you found will suspend the device. See the Documentation directory and/or http://lwn.net/Articles/373550/ Regards Oliver -- 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
