Touchpad not working on Lenovo ThinkPad L580 after upgrade to 19.04

[Max Schumann]

After upgrading from 18.10 to 19.04 the touch pad stopped working during the upgrade.
cat /proc/bus/input/devices does not show any information about the Synaptics Touchpad.
lsusb does show an entry:
Bus 001 Device 006: ID 06cb:009a Synaptics, Inc.

synclient shows:
Couldn't find synaptics properties. No synaptics driver loaded?

ProblemType: Bug
DistroRelease: Ubuntu 19.04
Package: linux-image-5.0.0-13-generic 5.0.0-13.14
ProcVersionSignature: Ubuntu 5.0.0-13.14-generic 5.0.6
Uname: Linux 5.0.0-13-generic x86_64
ApportVersion: 2.20.10-0ubuntu27
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: max 1990 F.... pulseaudio
CurrentDesktop: ubuntu:GNOME
Date: Sun Apr 21 08:32:38 2019
InstallationDate: Installed on 2019-04-10 (10 days ago)
InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.3)
MachineType: LENOVO 20LW0010GE
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.0.0-13-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash vt.handoff=1
RelatedPackageVersions:
 linux-restricted-modules-5.0.0-13-generic N/A
 linux-backports-modules-5.0.0-13-generic N/A
 linux-firmware 1.178
SourcePackage: linux
UpgradeStatus: Upgraded to disco on 2019-04-20 (0 days ago)
dmi.bios.date: 09/25/2018
dmi.bios.vendor: LENOVO
dmi.bios.version: R0QET49W (1.26 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20LW0010GE
dmi.board.vendor: LENOVO
dmi.board.version: SDK0J40697 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvrR0QET49W(1.26):bd09/25/2018:svnLENOVO:pn20LW0010GE:pvrThinkPadL580:rvnLENOVO:rn20LW0010GE:rvrSDK0J40697WIN:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad L580
dmi.product.name: 20LW0010GE
dmi.product.sku: LENOVO_MT_20LW_BU_Think_FM_ThinkPad L580
dmi.product.version: ThinkPad L580
dmi.sys.vendor: LENOVO

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[AaronMa (mapengyu)]

Could you try passing the following parameter in kernel cmdline:

psmouse.elantech_smbus=0

Please attach dmesg with test result.

[Kai-Heng Feng (kaihengfeng)]

Please test this kernel:
https://people.canonical.com/~khfeng/lp1825699/

[Max Schumann (max-schumann1990)]

The kernel paramter "psmouse.elantech_smbus=0" did the trick.
Thank you very much. No need to downgrade.