Public bug reported: Dell Latitude 7490 I2C touchpad (DELL081C:00 044E:121F) intermittently reports invalid position data, causing left-click and scroll to stop working. libinput logs "kernel bug: Touch jump detected and discarded" errors.
== HARDWARE == Laptop: Dell Latitude 7490 CPU: Intel Core i5-8250U Touchpad: DELL081C:00 044E:121F (Alps I2C HID) - Vendor: 044E (Alps Electric) - Product: 121F - Bus: I2C (0018) - Driver: hid-multitouch - Path: /devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-1/i2c-DELL081C:00 == SYMPTOMS == 1. Left-click stops responding intermittently (tap-to-click and physical) 2. Two-finger scroll stops working intermittently 3. Issue affects BOTH touchpad AND external USB mouse 4. Occurs on both Wayland and X11 sessions 5. Resolves temporarily after a few seconds == ERROR LOGS == === Touch Jump Detection (Primary Issue) === gnome-shell: libinput error: event6 - DELL081C:00 044E:121F Touchpad: kernel bug: Touch jump detected and discarded. See https://wayland.freedesktop.org/libinput/doc/1.25.0/touchpad-jumping-cursors.html for details gnome-shell: libinput error: event6 - DELL081C:00 044E:121F Touchpad: WARNING: log rate limit exceeded (5 msgs per 24h). Discarding future messages. === Event Processing Lag === gdm-x-session: (EE) event6 - DELL081C:00 044E:121F Touchpad: client bug: event processing lagging behind by 21ms, your system is too slow === Device Removal/Reinitialization === gdm-x-session: (II) event6 - DELL081C:00 044E:121F Touchpad: device removed kernel: input: DELL081C:00 044E:121F Touchpad as /devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-1/i2c-DELL081C:00/0018:044E:121F.0001/input/input9 kernel: hid-multitouch 0018:044E:121F.0001: input,hidraw0: I2C HID v1.00 Mouse [DELL081C:00 044E:121F] on i2c-DELL081C:00 == DEVICE INFO == From /proc/bus/input/devices: N: Name="DELL081C:00 044E:121F Touchpad" P: Phys=i2c-DELL081C:00 S: Sysfs=/devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-1/i2c-DELL081C:00/0018:044E:121F.0001/input/input9 H: Handlers=mouse1 event6 B: PROP=1 B: EV=1b B: KEY=e520 30000 0 0 0 0 B: ABS=2e0800000000003 B: MSC=20 I: Bus=0018 Vendor=044e Product=121f Version=0100 == ANALYSIS == Per libinput docs, "Touch jump detected" means kernel driver reports physically impossible position coordinates (large jumps between consecutive reports). Likely cause: Bug in hid-multitouch or i2c-hid driver for this specific Alps touchpad. == SOFTWARE VERSIONS == - Ubuntu 24.04.3 LTS - Kernel: 6.14.0-36-generic (linux-image-generic-hwe-24.04) - libinput: 1.25.0 - GNOME Shell with mutter 46.2 == STEPS TO REPRODUCE == 1. Use Dell Latitude 7490 with built-in touchpad 2. Normal usage - clicking and scrolling 3. Intermittently, clicks and scrolls stop registering 4. Check journalctl for "Touch jump detected" errors == WORKAROUNDS ATTEMPTED == - Tested on Wayland and X11: issue persists on both - Disabled GNOME extensions: issue persists ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: alps dell hid-multitouch i2c-hid touchpad -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2134345 Title: [Dell Latitude 7490] I2C touchpad reports invalid position data - "Touch jump detected" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2134345/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
