On Fri, Jun 08, 2012 at 09:53:20AM +0200, Bjørn Mork wrote: > Bjørn Mork <bjorn@xxxxxxx> writes: > > Bjørn Mork <bjorn@xxxxxxx> writes: > >> Italo Migotto <imigotto@xxxxxxxxx> writes: > >> > >>> they are modems. yes, I only use one of the interfaces, but couldn´t > >>> find a way to unbind individual interfaces, only the whole device. > >> > >> You can unbind individual ports like this: > >> > >> echo ttyUSB0 > /sys/bus/usb-serial/drivers/<drivername>/unbind > > > > Sorry. That didn't work as expected. Should be fixed... > > ... or maybe not. > > Took a quick peek at drivers/usb/serial/bus.c and became more confused. > usb_serial_device_remove() will just unregister the tty device, and > usb_serial_device_probe() will the let you register it again. So you > save a tty device, but unbinding from the usb-serial driver this way > doesn't free any other resources. In particular not the precious ttyUSB > minors. > > I find that behaviour a bit confusing. I did expect that unbinding > would cause all resources related to the unbound port to be freed and > made available for other drivers and/or devices. > > But I don't see any way this can be changed either. If we propagate the > unbind to the usb driver, then there is no way to keep usb-serial "bind" > working like before. And I guess that's not acceptable... Yeah, I don't think we can really do this properly, as we allow multiple minors to a single device, and sometimes, we control them together through the same interface. If the device has multiple interfaces, it should work by handling the bind/unbind from the USB driver layer, not the USB-Serial layer. thanks, greg k-h -- 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
