[BUG] Touchpad not detected on linux-cachyos 7.1.1 (regression from 7.0.12) — ThinkPad Z13 Gen 1, works on 6.18-LTS

[AndreasKoestler]

Summary

After updating linux-cachyos from 7.0.12-1 → 7.1.1-2, the touchpad is no longer detected at all. Only the TrackPoint enumerates. Booting linux-cachyos-lts 6.18.36-1 (same system, same linux-firmware) fully restores the touchpad, so this is a kernel regression in the 7.1.x series, not a firmware/userspace issue.

Hardware

• Model: Lenovo ThinkPad Z13 Gen 1 (21D2CTO1WW)
• CPU: AMD Ryzen 7 PRO 6860Z
• BIOS: N3GET79W (1.79), 2026-04-28
• Pointing devices: Elan TrackPoint + touchpad, behind the i8042/PS/2 AUX port; Wacom touchscreen (unaffected)

Versions

	Version	Touchpad
Bad	linux-cachyos 7.1.1-2	not detected
Good	linux-cachyos 7.0.12-1 (previous)	works
Good	linux-cachyos-lts 6.18.36-1	works

linux-firmware / amd-ucode are identical across the good and bad boots (both at 20260622), ruling out firmware.

Symptoms / evidence (on 7.1.1-2)

/proc/bus/input/devices contains no touchpad node — only TPPS/2 Elan TrackPoint, the keyboard, and the Wacom touchscreen.

Kernel log shows psmouse registering only the TrackPoint on serio1, with no Synaptics/touchpad detection line preceding it and no RMI/SMBus handoff:

psmouse serio1: trackpoint: Elan TrackPoint firmware: 0x00, buttons: 3/3
input: TPPS/2 Elan TrackPoint as /devices/platform/i8042/serio1/input/input8

On 6.18.36-LTS the touchpad enumerates normally on the same boot path.

What was already tried (no effect on 7.1.1)

• modprobe -r psmouse && modprobe psmouse — re-probes serio1, still only finds the TrackPoint
• modprobe psmouse synaptics_intertouch=1 — no change
• Confirmed no modprobe blacklist, synaptics_intertouch=-1 (auto), keyboard layout normal
• Touchpad is not appearing on any I2C-HID or SMBus/RMI4 address either

Suspected area

i8042 / psmouse touchpad (Synaptics/RMI) detection regressed somewhere between 7.0.12 and 7.1.1. Similar in spirit to #858.

Happy to help

I can provide full dmesg, run with psmouse.* debug params, or do a git bisect between 7.0.12 and 7.1.1 if that would help narrow it down.

[ptr1337]

Issue is likely introduced by 9a98ebe630cf (input: trackpoint - Enable doubletap by default on capable devices)

Here is a patch, which disables it for your laptop. Do you know how to compile a kernel?
If not please let me know, then I can compile it for you

thinkpad.patch

[AndreasKoestler]

Update — found a working boot-time fix, and a correction to the hardware details.

Correction: the touchpad is Elan I2C-HID, not Synaptics PS/2

I misidentified it in the original post. The touchpad is:

ELAN06A0:00 04F3:3231 Touchpad — on i2c-2 (AMDI0010:02), driven by i2c-hid / hid-multitouch

The only PS/2 device on serio1 is the Elan TrackPoint (which is unaffected).

Fix: psmouse.synaptics_intertouch=0 restores the touchpad on 7.1.1

Booting 7.1.1-2 with psmouse.synaptics_intertouch=0 on the kernel command line brings the touchpad up normally, with full multitouch:

input: ELAN06A0:00 04F3:3231 Touchpad as /devices/platform/AMDI0010:02/i2c-2/i2c-ELAN06A0:00/0018:04F3:3231.0001/input/input11

┌───────────────────────────────┬─────────────────────────┬────────────────┐
│ Kernel │ Default (intertouch=-1) │ intertouch=0 │
├───────────────────────────────┼─────────────────────────┼────────────────┤
│ linux-cachyos 7.1.1-2 │ touchpad absent │ touchpad works │
├───────────────────────────────┼─────────────────────────┼────────────────┤
│ linux-cachyos 7.0.12-1 (prev) │ works │ — │
├───────────────────────────────┼─────────────────────────┼────────────────┤
│ linux-cachyos-lts 6.18.36-1 │ works │ — │
└───────────────────────────────┴─────────────────────────┴────────────────┘

Why this is interesting

A psmouse/i8042 intertouch parameter gates whether an I2C-HID touchpad enumerates. That strongly suggests psmouse's intertouch/SMBus probing in 7.1.x is racing with / interfering with the I2C-HID touchpad probe on the AMD I2C controller — i.e. the regression between 7.0.12 and 7.1.1 is in that interaction, not in the touchpad driver itself.

Happy to provide full dmesg with and without the param, test debug parameters, or git bisect 7.0.12 → 7.1.1.

(Also: could a maintainer add the bug label? Thanks.)

[AndreasKoestler]

Thank you for your fast reaction to this. You've created the patch faster than I could pin-point the issue. I have a workaround for now (previous comment).

[ptr1337]

Thank you for your fast reaction to this. You've created the patch faster than I could pin-point the issue. I have a workaround for now (previous comment).

It would be better to handle it with the patch and potentially also fix it in the normal kernel then.

[AndreasKoestler]

Ok, I will apply the patch, compile the kernel, and report back. It probably won't happen today though.