Hello, I am stumbling onto this bug in LTS 24.04 & 26.04 for this specific modem too, but I suspect this would happen with others too.
I've been digging the issue and noticed that the `[email protected]` was quickly restarting and being killed when the modem was plugged in, likely because `udev` triggers this service's restart fast (add & change events happening back to back). It seems that the usage of a systemd unit for usb-modeswitch, combined with the fact that `/usr/lib/udev/usb_modeswitch` uses `systemctl --no- block restart` makes systemd kill the unit mid-run and end-up putting the modem to mode `0` (as confirmed by `bConfigurationValue` being empty), but doesn't then transition to mode `3`, disabling the modem entirely. I checked that removing the `--no-block` switch from `/usr/lib/udev/usb_modeswitch` indeed prevented units from being killed and restored functionality; since restarts happened sequentially rather than concurrently. This might be a fix, however I fail to understand the implications of waiting for such units to complete in udev. In the meantime what I did to prevent that temporarily and restore functionality in my system was to symlink `/usr/share/usb_modeswitch/12d1:15c1` to `/dev/null` to disable usb- modeswitch for the modem and let it be in it's default mode of `2`, which worked. Cheers. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1940377 Title: The WWAN - Huawei Technologies Co., Ltd. [12d1:15c1] does not work after install Ubuntu Hirsute. To manage notifications about this bug go to: https://bugs.launchpad.net/oem-priority/+bug/1940377/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
