Debian discussion to disable automatic TTY probing

Dan Williams dcbw at
Thu Sep 28 17:46:59 UTC 2017

On Thu, 2017-09-28 at 19:16 +0200, Bjørn Mork wrote:
> Just one other idea: Why not look at the kernel driver? It should
> give
> you a pretty good idea about which devices are modems.
> 'option', 'sierra', 'qcserial' are all pretty much guaranteed to be
> modems. 'pl2303', 'ftdi_sio', 'io_edgeport' are likely not. Except if
> you have an old serial modem behind them..

Yeah, that's generally what MM does already.  I detailed the problem
cases in my other mail.  It's actually the case that
pl2303/ftdi_sio/cp210x are often used as generic USB/serial converters
for modems.  Hence we "greylist" these drivers and only probe them on-
demand.  Plus there are quite a few ACM devices that aren't modems
either, but also a lot of modems that are ACM.

Plus there's modems that aren't in the kernel drivers yet, or aren't in
 some old kernel driver, so people do the magic 'bind' thing for usb-
serial that's everywhere on the internet.


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