Been having issues with mouse devices since the switch to SystemD.
My Logitech G400 mouse works on the GDM menu for a few seconds, then stops. Re-plugging the mouse does not bring it back, though it does still show under lsusb.
Maybe in a related issue, my touchpad has a bad connection cable, and this occasionally causes it to 'replug'. In the past, this would mean a brief interruption to input before it'd return to normal. Now, when it resyncs, it loses all it's multitouch and sensitivity settings.
Dmesg shows this
[ 67.836360] psmouse serio4: TouchPad at isa0060/serio4/input0 lost sync at byte 1
[ 67.838414] psmouse serio4: TouchPad at isa0060/serio4/input0 lost sync at byte 1
[ 67.980887] psmouse serio4: TouchPad at isa0060/serio4/input0 lost sync at byte 1
[ 67.982372] psmouse serio4: TouchPad at isa0060/serio4/input0 lost sync at byte 1
[ 67.982379] psmouse serio4: issuing reconnect request
[ 72.426910] psmouse serio4: TouchPad at isa0060/serio4/input0 lost synchronization, throwing 2 bytes away.
[ 72.933191] psmouse serio4: resync failed, issuing reconnect request
[ 79.161005] psmouse serio4: synaptics: hardware appears to be different: id(280343-280343), model(123057-123057), caps(d04733-d04733), ext(e40000-264).
[ 79.865072] psmouse serio4: synaptics: Unable to query device.
[ 81.744968] input: PS/2 Synaptics TouchPad as /devices/platform/i8042/serio4/input/input15
Maybe something to do with the different ID? It's been going on since the switch to Systemd. The mouse issue seems intermittent, maybe one in every three boots it works normally and stays working.
Been testing it. It does appear to work if I suspend and resume the laptop.
Just a quick update, this issue seems to have been related to laptop-mode-tools
Removing laptop-mode-tools fixed the issue
Making changes to autosuspend settings in configurations for laptop-mode-tools didn't seem to have any effect.