Apologies if this ought to have gone to the USB maintainer (but his auto-reply implies not). I'm particularly interested in drivers/usb/core/config.c which appears to enforce the USB specification by refusing to allow a low speed CDC ACM. (Comment "Some buggy low-speed devices ...", at about line 300.) However, such devices exist and some are potentially quite useful (such as Arduinos & digistump). Various people have posted about not being able to use them with Linux and I think the above file is the reason (another well known OS family allows them). I'd like to ask if there's a sane (Linux) way to allow them or are you open to one being created? If so, as I don't know the best way then if you have any ideas I'd certainly be pleased to hear them. Some sort of quirk? To make it easy for non-expert/novice Linux users to connect non-conforming USB devices and have them "just work" please consider a way that is either the default or easy, i.e. so they don't have to config/build a kernel. I am a bit surprised that the code does what it currently does, as it basically makes such devices unusable so far as I can tell and may as well just reject them entirely. Thanks, John -- 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