#Goals

• make the bm818 modem in the Librem5 more reliable to the user
• minimum impact on the system if not needed (anymore)
• works on postmarketOS and PureOS

#workaround for

#bug in xhci-usb that makes the whole usb hub disappear from the bus

• https://source.puri.sm/Librem5/linux/-/issues/303
• affects also sdcard connected to the same hub as the modem

Since the brief disconnects of the Modem seem to be fixed (see 'https://source.puri.sm/Librem5/linux/-/merge_requests/672' above) it is unlikely that this bug will trigger.

#other issues

Please look at the development branch for a list and ongoing work to find workaround for those.

#Dependencies

Dependencies should be pulled in by the package manager, if not installed manually.

• udev - catch events of hardware disappearing
• at - run long running script from udev rule
• daemontools - setlock to ensure scripts run only one instance at time (postmarketOS: only in edge repository)
• kmod - modprobe, rmmod
• bsdutils (logger) - logging
• libnotify-bin - sending notifications using notify-send
• util-linux - su for notification

#Feedback/Issues

Issues and general feedback can be filed here: https://todo.sr.ht/~chrichri/librem5-bm818-watchmodem

#Installation (until packaging is done)

#PureOS/Debian package

can be found here:

#manual installation in PureOS

• install dependencies: sudo apt-get install udev at daemontools kmod bsdutils libnotify-bin util-linux
• copy these two files from this repo
  • udev/42-librem5-watch-xhci-usb.rules → /etc/udev/rules.d/42-librem5-watch-xhci-usb.rules
  • script/librem5-recover-xhci-usb.sh → /usr/local/sbin/librem5-recover-xhci-usb.sh
• copy xpub.sh from https://github.com/Ventto/xpub to /usr/local/sbin
• run sudo udevadm control -R

#manual installation in postmarketOS

• still missing - you care to share what did different from the steps above ;-) ?