On Fri, 2013-06-07 at 17:43 +0400, Dmitry Ivanyushin wrote:ModemManager does not use lockfiles as there are various well-understood
> I am working with git version of MM and Ubuntu 12.04.
>
> I have three different physical serial (RS232) ports and they are not
> USB-to-serial. Now MM probes all of them. I want MM to automatically detect
> the port the modem is connected to but there're another devices controlled
> by another daemon.
>
> If there were lock files, my daemon wouldn't probe the ports which are
> locked by MM and vice-versa.
problems with them. Â It does, however use TIOCEXCL which any other
program using doing serial stuff should probably be doing too. Â Doing it
through the ioctl means there are no stale lock files left if something
crashes and no need to write stuff out to random places.
Dan
>
> 2013/6/7 Aleksander Morgado <aleksander lanedo com>
>
> >
> > > I have several serial ports in my system but also I have a daemon that
> > > is responsible for communication with several devices connected to those
> > > serial ports. This daemon runs as root. However when MM starts it tries
> > > to find modem via writing to all serial ports registered in the system.
> > > That operation break protocols of these devices.
> > >
> > > I am thinking of adding support of lock-files to MM. Is it good to add
> > > such support in mm-manager.c to test locks, in mm-serial-port to acquire
> > > and release those locks?
> > >
> >
> > What MM version is this? MM shouldn't be probing platform serial (RS232)
> > ports by default, unless they are explicitly white-listed. For USB
> > devices exposing ttys which aren't modems, we can blacklist them in our
> > udev rules. Would that help?
> >
> > --
> > Aleksander
> >