Public bug reported: Clean regression between two consecutive Ubuntu HWE kernel builds on the same hardware and userspace. Working: linux-image-6.17.0-22-generic (used daily since 23 April 2026, ~12 days of normal use) Broken: linux-image-6.17.0-23-generic (installed 5 May 2026, broken across 4 boots, reverted) Symptom: On 6.17.0-23, the touchpad's physical buttons register click events normally, but finger motion produces no events at all — evtest shows BTN_* events on click but no ABS_X / ABS_MT_POSITION_X / SYN_REPORT data when sliding. The TrackPoint on the same machine continues to work fine. Booting back into 6.17.0-22 fully restores touchpad motion. No userspace, BIOS, or hardware changes between the two boots. Hardware:
Lenovo ThinkPad P14s Gen 1 (machine type 20Y2S09P00) BIOS: R1BET77W (1.46) Touchpad: Synaptics LEN2064 PNP0f13, fw 10.32, model 1, board id 3471, fw id 3972349 Driver path: psmouse / serio1 (PS/2) Distribution: Linux Mint on Ubuntu 24.04 (noble), HWE kernel series 6.17. Boot history (abbreviated): reboot 6.17.0-22 Tue May 5 20:47 still running reboot 6.17.0-23 Tue May 5 20:43 - 19:43 reboot 6.17.0-23 Tue May 5 20:38 - 19:42 reboot 6.17.0-23 Tue May 5 20:32 - 19:36 reboot 6.17.0-23 Tue May 5 20:14 - 19:31 reboot 6.17.0-22 Wed Apr 29 21:19 - 22:47 (5+01:27) reboot 6.17.0-22 Sun Apr 26 17:42 - 22:47 (8+05:04) ... (-22 working continuously back to Apr 23) Workarounds tried on -23, none successful: psmouse.synaptics_intertouch=1 (suggested by the kernel itself in the dmesg hint) modprobe psmouse proto=exps modprobe -r psmouse && modprobe psmouse Disabling all xinput startup entries Confirmed Device Enabled: 1, Send Events Mode Enabled: 0, 0 in xinput properties dmesg excerpt (identical between -22 and -23 — probe looks the same): psmouse serio1: synaptics: queried max coordinates: x [..5678], y [..4694] psmouse serio1: synaptics: queried min coordinates: x [1266..], y [1162..] psmouse serio1: synaptics: Your touchpad (PNP: LEN2064 PNP0f13) says it can support a different bus. If i2c-hid and hid-rmi are not used, you might want to try setting psmouse.synaptics_intertouch to 1 and report this to [email protected]. psmouse serio1: synaptics: Touchpad model: 1, fw: 10.32, id: 0x1e2a1, caps: 0xf014a3/0x940300/0x12e800/0x500000, board id: 3471, fw id: 3972349 psmouse serio1: synaptics: serio: Synaptics pass-through port at isa0060/serio1/input0 input: SynPS/2 Synaptics TouchPad as /devices/platform/i8042/serio1/input/input6 The probe is clean on both kernels — the regression is in event reporting, not device registration. Reproducer: Boot 6.17.0-23. sudo evtest /dev/input/eventN on the SynPS/2 Synaptics TouchPad node. Slide finger on touchpad → no ABS coordinate events. Press buttons → BTN_LEFT / BTN_RIGHT events appear normally. Reboot into 6.17.0-22, repeat → ABS events appear, motion works. Notes: The -23 changelog as published does not contain any obvious input/psmouse/synaptics/serio/HID/i8042 entries (only CVE-2026-23231, CVE-2026-23209, CVE-2026-23112, and an AMD GPU fix LP: #2144522). If those are genuinely the only changes, the regression may stem from a build/config difference rather than a source change. ** Affects: linux (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2151260 Title: [regression] Synaptics LEN2064 touchpad motion stops working on 6.17.0-23 (works on 6.17.0-22) — ThinkPad P14s Gen 1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2151260/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
