Bug#762396: systemd: serial devices /dev/ttyS2 and /dev/ttyS3 do not work

[M G Berberich]

Hello,

Am Sonntag, den 21. September schrieb Michael Biebl:
> Am 21.09.2014 um 22:23 schrieb M G Berberich:
> > Package: systemd
> > Version: 208-8
> > Severity: normal
> > 
> > Dear Maintainer,
> > 
> > I have a card with two additional serial devices in the system, giving
> > /dev/ttyS2 and /dev/ttyS3. One with a thermal sensor and one with a
> > serial terminal. These serial devices do not work when the system is
> > started with systemd. They do work fine if sysvinit is used.
> 
> Looking at the systemd-analyze dump, I see
>
…
>
> The devices seem to be functional, but maybe the getty on ttyS2
> interferes with what you want to do with ttyS2?

No, on ttyS2 there is a serial Terminal (VT320), so this is O.K.

But I found the problem:
It was modemmanager, which was _automatically_ installed. Modemmanager
screwed up ttyS3 and ttyS2 (perhaps the onboard ttyS0 and ttyS1 also,
but I can’t tell, because there is no device on ttyS0 and ttyS1 does
not even have a connector). Probably systemd/modemmanager/dbus assumes
that there must be a modem understanding AT-commands behind every
serial interface. Uninstalling modemmanager does the job.

	MfG
	bmg

-- 
„Des is völlig wurscht, was heut beschlos- | M G Berberich
 sen wird: I bin sowieso dagegn!“          | berberic at fmi.uni-passau.de
(SPD-Stadtrat Kurt Schindler; Regensburg)  | www.fmi.uni-passau.de/~berberic