Also observed on Ubuntu 18.04.3, with kernel 5.0.0-37-generic -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to modemmanager in Ubuntu. https://bugs.launchpad.net/bugs/1827328
Title: ModemManager does not honor blacklisted ttys (ID_MM_DEVICE_IGNORE) Status in modemmanager package in Ubuntu: Confirmed Bug description: In Ubuntu 19.04 (and likely earlier) Modem Manager is installed with filter policy 'strict' as opposed to 'default', which actually makes Modem Manager _less_ strict regarding explicitly blacklisted ttys (see man modemmanager). This means that ttys, that are explicitly blacklisted from Modem Manager by using ENV{ID_MM_DEVICE_IGNORE}="1" in its udev rule is still opened and probed by Modem Manager although it should not. This is a common cause of problems and frustrations for people working with actual serial devices, e.g. within embedded development (e.g. Arduino and the like). See https://nick.zoic.org/art/failed-to-set- dtr-rts-systemd-modemmanager/ for an example. A proposed solution is to change the following line in: /lib/systemd/system/ModemManager.service from: ExecStart=/usr/sbin/ModemManager --filter-policy=strict to: ExecStart=/usr/sbin/ModemManager --filter-policy=paranoid ProblemType: Bug DistroRelease: Ubuntu 19.04 Package: modemmanager 1.10.0-1 [modified: lib/systemd/system/ModemManager.service] ProcVersionSignature: Ubuntu 5.0.0-13.14-generic 5.0.6 Uname: Linux 5.0.0-13-generic x86_64 ApportVersion: 2.20.10-0ubuntu27 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Thu May 2 15:35:58 2019 EcryptfsInUse: Yes InstallationDate: Installed on 2018-05-26 (340 days ago) InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426) ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: modemmanager UpgradeStatus: Upgraded to disco on 2019-04-18 (13 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/modemmanager/+bug/1827328/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp