Updated the description with the information requested in SRU template ** Description changed:
I have a DELL WWAN module (DW5580) on my platform. Normally it could be detect and used in Ubuntu 16.04 daily image. However it is sometimes unusable and can not be detected. After debugging, we found there is an upstream patch that can fix the issue: https://cgit.freedesktop.org/ModemManager/ModemManager/commit/?id=8a386218690aeff7e2c923a14f91da7bbc046ed2 Please merge the fix to modem manager to fix the issue. Ubuntu Xenial (daily image) Release: 16.04 modemmanager: Installed: 1.4.12-1ubuntu1 Candidate: 1.4.12-1ubuntu1 Version table: *** 1.4.12-1ubuntu1 500 500 http://archive.ubuntu.com/ubuntu xenial/main amd64 Packages 100 /var/lib/dpkg/status + + + + * 2017-06-20 Update details for SRU + + [Impact] + + DELL WWAN module (DW5580) is sometimes unusable and can not be detected + by ModemManager. + + The fix consisted in the correct initialization of a "retry" variable in + modem's probing. Without this initialization, the "retry" variable might + assume random big values, forcing the modem to retry the same step a + semi-infinite number of times. + + + [Test Case] + + 1. Start/restart the ModemManager service with debug messages enabled + + a. Open ModemManager.service file and add the flag --debug to the ExecStart entry + + ExecStart=/usr/local/sbin/ModemManager --debug + + b. run systemctl daemon-reload + c. run systemctl restart Modemmanager + + 2. Connect Dell WWAN module DW5580 (if the modem is integrated, skip this step) + 3. Open ModemManager logs: + + journalctl -fu ModemManager + + 4. ModemManager logs show that the service is continuously sending AT + command "AT+CGMI" preventing the modem to be recognized + + + [Regression Potential] + + Considering the nature of the fix (a variable that was not initialized), + I can not think of a real potential regression and the patch has been + tested and showed no issues so far. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1567796 Title: It is sometimes unable to find DELL WWAN module. To manage notifications about this bug go to: https://bugs.launchpad.net/oem-priority/+bug/1567796/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
