RFC: New device filter policies

[Aleksander Morgado]

Hey!

>
> Following the discussion regarding Debian wanting to patch
> ModemManager to avoid unnecessary probing of non-modem TTYs, I ended
> up preparing a branch that implements a set of "filter policies"
> composed of different "filter rules".
>
> See documentation for the filter rules here:
> https://www.freedesktop.org/software/ModemManager/api/1.8.0/ref-overview-modem-filter.html
>
> And documentation for the filter policies here:
> https://www.freedesktop.org/software/ModemManager/api/1.8.0/ch03s02.html
>
> By default ModemManager would use the "DEFAULT" filter policy, which
> is equivalent to the logic we've been using in previous releases. But
> these patches also allow stricter policies (e.g. the "STRICT" one)
> that would not allow probing of non-modem TTYs (but may also not allow
> probing of modem TTYs not covered by the default heuristics!).
>
> This is now implemented in the "device-filter-policies" branch in my
> github repo:
> https://github.com/aleksander0m/ModemManager/commits/device-filter-policies
>
> One quick test that you all may do would be to build ModemManager from
> this branch and run it in STRICT mode, and see if your modems are
> still completely probed and that non-modem TTYs aren't probed:
> # /usr/sbin/ModemManager --filter-policy=STRICT --debug
>
> Comments?
>
> P.S.: didn't fully test this myself with all my modems, and in
> particular, I have no idea how it will behave with bluetooth DUN
> devices.
>

I plan to get this merged to git master sometime this week; tests and
comments welcome!

Things that can be tested:

0) Run MM git master, e.g. /usr/sbin/ModemManager --debug
 * Take note of how the modem is detected, e.g. store mmcli -m 0 output.
 * Take note of which modem ports are probed.
 * Take note of which primary protocol is used to manage the modem,
e.g. QMI, or AT...

1) Build from the "device-filter-policies" branch and run in default
mode, e.g. /usr/sbin/ModemManager --debug
 * Does your modem get detected as before? (e.g. is mmcli -m 0 output the same?)
 * Are all ports probed in the same way as before? (e.g. are ports
that are NOT probed?)
 * Is the modem managed in the same way as before (e.g. QMI, or AT...)
 * Any problem seen?

2) Build from the "device-filter-policies" branch and run in STRICT
mode, e.g. /usr/sbin/ModemManager --filter-policy=STRICT --debug
 * Does your modem get detected as before? (e.g. is mmcli -m 0 output the same?)
 * Are all ports probed in the same way as before? (e.g. are ports
that are NOT probed?)
 * Is the modem managed in the same way as before (e.g. QMI, or AT...)
 * Any problem seen?

-- 
Aleksander
https://aleksander.es