> -----Original Message----- > From: linux-usb-owner@xxxxxxxxxxxxxxx [mailto:linux-usb- > owner@xxxxxxxxxxxxxxx] On Behalf Of Dan Williams > Sent: woensdag 11 maart 2009 12:29 > To: Matthias Urlichs > Cc: oliver@xxxxxxxxxx; Greg KH; linux-usb@xxxxxxxxxxxxxxx > Subject: Re: [RFC PATCH] usb-serial/option: modem port types > > On Wed, 2009-03-11 at 12:15 +0100, Matthias Urlichs wrote: > > Hi, > > > > oliver@xxxxxxxxxx: > > > > Ideally we'd use a single port and multiplex the required > > > channels > > > > across it, but we live in a non-ideal world with > > > far-from-ideal device > > > > firmware. > > > > > [ Why are all your emails breaking up the indentation? > > Too-narrow terminal window? ] > > > > > Why do you want to > > > multiplex? > > > > > Because some devices export more capabilities in multiplex mode > > (working flow control, more than one auxiliary command port). > > > > Unfortunately, many others don't support multiplexing at all, are > buggy > > (esp. WRT flow control), don't support channel attribute discovery, > > are incapable of being switched out of multiplex mode without power > > cycling, and/or don't supply documentation for their particular > > implementation of the supposedly-standardized multiplex mode without > > signing a too-restrictive NDA. > > How does the GSM multiplexing capability show up? Do you just have to > know which device+firmware combinations support it, or can it be probed > somehow? In theory it can be probed with AT+CMUX=? to see the supported mux modes. But this only applies to the 3GPP TS 27.010 mux. Regards, Filip- -- 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
