Package: modemmanager Version: 1.6.4-1 Severity: normal ModemManager tries to detect serial modems by probing. This leads to unexpected behaviour of Microchip's USB-to-Serial bridges (in this case MCP2200), which are mostly used in hobbyists' projects. Probably a probing payload is sent which is accepted as input data by an interfacing microcontroller.
ModemManager reports problems during probing via syslog: Dec 28 19:03:04 linux ModemManager[531]: <info> Creating modem with plugin 'Generic' and '1' ports Dec 28 19:03:04 linux ModemManager[531]: <warn> Could not grab port (tty/ttyACM0): 'Cannot add port 'tty/ttyACM0', unhandled serial type' Dec 28 19:03:04 linux ModemManager[531]: <warn> Couldn't create modem for device at '/sys/devices/pci0000:00/0000:00:1a.0/usb3/3-1': Failed to find primary AT port Please update the Debian packages for stretch and sid to greylist such devices and prevent further disturbance. The file of interest is 'src/77-mm-usb-serial-adapters-greylist.rules' in the upstream project: git://anongit.freedesktop.org/ModemManager/ModemManager ssh://git.freedesktop.org/git/ModemManager/ModemManager https://anongit.freedesktop.org/git/ModemManager/ModemManager.git On line 15 to 16 it says: # Devices using Microchip's VID ATTRS{idVendor}=="04d8", ENV{ID_MM_DEVICE_MANUAL_SCAN_ONLY}="1" This includes the MCP2200 which has: VID: 04d8 PID: 00df Best regards Jonas K. -- System Information: Debian Release: 9.3 APT prefers stable-updates APT policy: (500, 'stable-updates'), (500, 'stable') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 4.9.0-4-amd64 (SMP w/2 CPU cores) Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE=de (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages modemmanager depends on: ii init-system-helpers 1.48 ii libc6 2.24-11+deb9u1 ii libglib2.0-0 2.50.3-2 ii libgudev-1.0-0 230-3 ii libmbim-glib4 1.14.0-1+b1 ii libmbim-proxy 1.14.0-1+b1 ii libmm-glib0 1.6.4-1 ii libpolkit-gobject-1-0 0.105-18 ii libqmi-glib5 1.16.2-1 ii libqmi-proxy 1.16.2-1 Versions of packages modemmanager recommends: ii usb-modeswitch 2.5.0+repack0-1 modemmanager suggests no packages. -- no debconf information
