On Tuesday 04 September 2012 15:45:36 Bjørn Mork wrote: > Oliver Neukum <oneukum@xxxxxxx> writes: > > > On Tuesday 04 September 2012 11:13:52 Bjørn Mork wrote: > > > > Hi, > > > >> there is some work going on trying to support CDC MBIM devices in > >> Linux ( http://www.usb.org/developers/devclass_docs/MBIM10.zip ) > > > > Yet another protocol. > > Yes. But this time with some hope of multi-vendor support, given that > Microsoft points to it for Windows 8 Mobile Broadband device support: > http://msdn.microsoft.com/en-us/library/windows/hardware/mbim-based-mobile-broadband-requirements-for-windows.aspx It can't be helped. Support for this will be needed. > Yes, I expect that major changes to cdc_ncm will be necessary, and > pointing to it could be wrong from my side? It just seemed natural to > try to reuse any existing code. No, that is perfectly all right. It seems to me that the API between usbnet and its subdrivers is not powerful enough to support CDC-NCM well. > >> found that the cdc-wdm subdriver interface must be extended somewhat for > >> this to be possible. At the very least, the main driver need to handle > >> some notifications which are ignored by cdc-wdm. And depending on which > > > > Which ones? > > The ones which are already handled by cdc_ncm I believe: > > USB_CDC_NOTIFY_NETWORK_CONNECTION and USB_CDC_NOTIFY_SPEED_CHANGE. > cdc-wdm will just debug print USB_CDC_NOTIFY_NETWORK_CONNECTION and > ignore it, but will log an error if it sees USB_CDC_NOTIFY_SPEED_CHANGE So provide callbacks for them. > yes. Reading the spec terrified me. Among other issues, it allows > multiplexing several IP connections over a single set of bulk in/out > endpoints, where an "IP connection" probably will have to map logically > to a network device. Yes, but given the capability of UMTS something like this would be needed. > I believe we can get away with the main driver only looking at messages > received from the device, without changing or filtering them. In hindsight, cdc-wdm should have used the tty layer. Then we'd now write a line discipline. > I see that I should have included the data interception hook, or not > have mentioned it at all. Sorry for any confusion. Very well. 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
