Am Freitag, 24. Juli 2009 16:19:41 schrieb Alan Cox: > On Fri, 24 Jul 2009 16:12:41 +0200 > > Oliver Neukum <oliver@xxxxxxxxxx> wrote: > > Am Freitag, 24. Juli 2009 14:48:05 schrieb Alan Cox: > > > > No, I was thinking of having two full devices, a data channel and a > > > > control channel for devices that really talk AT commands natively. > > > > > > If the hardware does it great, however for things like a 3G modem you > > > have the problem that the PPP is over the AT command channel which may > > > itself be multiplexed. And the muxing in question is *ugly* - sort of > > > HDLC and LAP-B done wrong. > > > > Well, yes, but we would really like a separate control channel, so we > > can query parameters like signal strength, while we do PPP over the data > > channel. > > Thats the notion of the AT mux stuff - you get multiple AT channels and > you can stuff PPP down one of them. It's still butt ugly. That is a problem. But is it so ugly that we'd forgo the added functionality rather than implement it in the kernel? If not, I maintain that we should not maintain several different control channel interfaces, like some devices use cdc-wdm, others a ttyUSB and the AT mux stuff shall use yet a different method. 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
