TOBY-L210 does not detected by ModemManager deamon at boot time

[Dan Williams]

On Mon, 2018-10-29 at 17:27 +0100, Aleksander Morgado wrote:
> Hey,
> 
> > > -----Original Message-----
> > > From: Aleksander Morgado <aleksander at aleksander.es>
> > > Sent: Monday, October 29, 2018 9:48 AM
> > > To: Baryshnikov, Maxim (Digiteq Automotive)
> > > <Maxim.Baryshnikov at digiteqautomotive.com>; modemmanager-
> > > devel at lists.freedesktop.org
> > > Subject: Re: TOBY-L210 does not detected by ModemManager deamon
> > > at boot
> > > time
> > > 
> > > On 10/23/18 8:19 PM, Baryshnikov, Maxim (Digiteq Automotive)
> > > wrote:
> > > > Hello all,
> > > >             I'm struggling with the following issue. On my
> > > > system, the
> > > 
> > > ModemManager (1.8.2) cannot detect TOBY-L2 modem at boot time. I
> > > have
> > > allowed all "filter rules", but the situation is the same as for
> > > the default rules set.
> > > However, if I manually reset the modem with detaching it from the
> > > system (send
> > > AT+CFUN=16 to it), the ModemManager successfully detects it.
> > > >             ModemManager is compiled with --without-mbim and
> > > > -without-qmi, but
> > > 
> > > there should be no influence on detection, I guess..
> > > >             Do you have any ideas what to check to solve this?
> > > > Is there something
> > > 
> > > wrong with udev? Thank you in advance for any piece of
> > > information..
> > > > Kind regards,
> > > 
> > > How are you sending AT+CFUN=16 to the modem while ModemManager is
> > > running? Please understand that no other program can be using the
> > > TTY port if you
> > > expect ModemManager to use it. Maybe you have a minicom session
> > > open while
> > > MM should be probing the port at the same time?
> > 
> > I don't think that this is happenning at the boot time. I've found
> > a workaround - to retrigger udev event on my device right after the
> > ModemManager service starts.
> > 
> > ExecStart=@sbindir@/ModemManager
> > ExecStartPost=/bin/udevadm trigger
> > /sys/devices/soc0/amba/e0002000.usb/ci_hdrc.0/usb1/1-1/1-1.2
> > 
> > 
> > > Without looking at the ModemManager debug log it's hard to say
> > > what's really
> > > happening. Could you get it?
> > > https://www.freedesktop.org/wiki/Software/ModemManager/Debugging/
> > 
> > I've found nothing much interesting there, it just does not probe
> > ttyACM ports without having an udev event detected first..
> > 
> > Oct 29 09:30:54 zynq7 ModemManager[179]: <debug>
> > [1540805454.220980] (tty/ttyACM0): adding device at sysfs path:
> > /sys/devices/soc0/amba/e0002000.usb/ci_hdrc.0/usb1/1-1/1-1.2/1-
> > 1.2:1.2/tty/ttyACM0
> > Oct 29 09:30:54 zynq7 ModemManager[179]: <debug>
> > [1540805454.221302] (tty/ttyACM0): port not candidate
> > Oct 29 09:30:54 zynq7 ModemManager[179]: <debug>
> > [1540805454.221565] (tty/ttyACM1): adding device at sysfs path:
> > /sys/devices/soc0/amba/e0002000.usb/ci_hdrc.0/usb1/1-1/1-1.2/1-
> > 1.2:1.2/tty/ttyACM1
> > Oct 29 09:30:54 zynq7 ModemManager[179]: <debug>
> > [1540805454.221874] (tty/ttyACM1): port not candidate
> > Oct 29 09:30:54 zynq7 ModemManager[179]: <debug>
> > [1540805454.222126] (tty/ttyACM2): adding device at sysfs path:
> > /sys/devices/soc0/amba/e0002000.usb/ci_hdrc.0/usb1/1-1/1-1.2/1-
> > 1.2:1.2/tty/ttyACM2
> > Oct 29 09:30:54 zynq7 ModemManager[179]: <debug>
> > [1540805454.222410] (tty/ttyACM2): port not candidate
> > 
> > That is probably a problem in udev on my system. It behaves wierd..
> > 
> 
> That totally looks like some udev related issue indeed. The "port not
> candidate" logs will happen if the ttyACM ports aren't flagged with
> ID_MM_CANDIDATE, which is one of the tags added by the ModemManager
> udev rules in /lib/udev/rules.d/. When the system boots and udev
> detects the devices, the rules should be executed and the tag added,
> and for some reason that is not happening in this setup.

udevadm control --log-priority=debug

and replug the device will let you see what udev is doing and why
certain ports may/may not be getting tagged correctly.

Dan