Comment 16 for bug 1795292

acpidump:
    5B10: 39 5F 48 49 44 00 A0 13 93 54 43 50 44 0A 02 A4 9_HID....TCPD...
    5B20: 0D 53 59 4E 41 33 32 35 35 00 A0 13 93 54 43 50 .SYNA3255....TCP
    5B30: 44 0A 03 A4 0D 41 4C 50 53 31 32 31 45 00 A4 0D D....ALPS121E...
    5B40: 45 4C 41 4E 34 36 39 44 00 08 45 49 43 30 11 21 ELAN469D..EIC0.!
    5B50: 0A 1E 8E 19 00 01 00 01 02 00 00 01 06 00 80 1A ................
    5B60: 06 00 15 00 5C 5F 53 42 2E 49 32 43 44 00 79 00 ....\_SB.I2CD.y.
    5B70: 08 53 49 43 30 11 21 0A 1E 8E 19 00 01 00 01 02 .SIC0.!.........

Upon installing libinput, and uninstalling synaptics, all mention of ELAN has disappeared from dmesg, and /dev/input shows nothing related to mouse/ touchpad.

Hardware debugging told me nothing useful, other than the device is physically there and receiving power.