Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> writes: > Any attempt to use a suspended device will return an error, whether the > port is powered off or not. The driver has to resume the device before > using it, and Sarah is proposing that this should cause the port to > power back on. Assuming that "powering off" a port means removing power from any bus powered device, won't this be something completely different from doing a USB resume or reset_resume? Complex devices may choose to keep parts of the system running while "suspended" in the USB bus context. Removing power will prevent this if the device is bus powered (which I believe you never know as there are too many devices lying about this for various reasons). Even if a driver support reset_resume, that only means that the driver knows how to recreate the device state after a USB bus reset. It does *not* mean that the driver knows how to recreate the device state after a cold boot of the device. That is in general not possible. The only way is usually to reinitialize from scratch. I.e. disconnect. Somehow I am pretty sure that nothing of this is news to any of you, so I am now sitting here wondering what part of this discussion I've completely misunderstood... Bjørn -- 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
