# kernel bug: Touch jump detected and discarded [solved]

## josephg

So now that I've become a bit more observant looking for kernel bugs, I found something in my Xorg.0.log the tail end of which is below

```
[    41.366] (II) config/udev: Adding input device SynPS/2 Synaptics TouchPad (/dev/input/event7)

[    41.366] (**) SynPS/2 Synaptics TouchPad: Applying InputClass "libinput touchpad catchall"

[    41.366] (**) SynPS/2 Synaptics TouchPad: Applying InputClass "libinput touchpad catchall"

[    41.366] (II) Using input driver 'libinput' for 'SynPS/2 Synaptics TouchPad'

[    41.366] (**) SynPS/2 Synaptics TouchPad: always reports core events

[    41.366] (**) Option "Device" "/dev/input/event7"

[    41.366] (**) Option "_source" "server/udev"

[    41.367] (II) event7  - SynPS/2 Synaptics TouchPad: is tagged by udev as: Touchpad

[    41.367] (II) event7  - SynPS/2 Synaptics TouchPad: device is a touchpad

[    41.368] (II) event7  - SynPS/2 Synaptics TouchPad: device removed

[    41.383] (**) Option "Tapping" "On"

[    41.383] (**) Option "config_info" "udev:/sys/devices/platform/i8042/serio1/input/input6/event7"

[    41.383] (II) XINPUT: Adding extended input device "SynPS/2 Synaptics TouchPad" (type: TOUCHPAD, id 10)

[    41.384] (**) Option "AccelerationScheme" "none"

[    41.384] (**) SynPS/2 Synaptics TouchPad: (accel) selected scheme none/0

[    41.384] (**) SynPS/2 Synaptics TouchPad: (accel) acceleration factor: 2.000

[    41.384] (**) SynPS/2 Synaptics TouchPad: (accel) acceleration threshold: 4

[    41.385] (II) event7  - SynPS/2 Synaptics TouchPad: is tagged by udev as: Touchpad

[    41.385] (II) event7  - SynPS/2 Synaptics TouchPad: device is a touchpad

[    41.386] (II) config/udev: Adding input device PC Speaker (/dev/input/event3)

[    41.386] (II) No input driver specified, ignoring this device.

[    41.386] (II) This device may have been added with another device file.

[   193.069] (II) Axis 0 value 5734 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[  2133.682] (EE) event7  - SynPS/2 Synaptics TouchPad: kernel bug: Touch jump detected and discarded.

See https://wayland.freedesktop.org/libinput/doc/1.10.7/touchpad_jumping_cursor.html for details

[  3213.553] (II) Axis 0 value 5735 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[  6213.716] (II) Axis 0 value 5725 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[  9213.756] (II) Axis 0 value 5695 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 11609.810] (EE) event7  - SynPS/2 Synaptics TouchPad: kernel bug: Touch jump detected and discarded.

See https://wayland.freedesktop.org/libinput/doc/1.10.7/touchpad_jumping_cursor.html for details

[ 12259.200] (II) Axis 0x1 value 4604 is outside expected range [1255, 4600]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 15272.829] (II) Axis 0 value 5673 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 18285.236] (II) Axis 0 value 5688 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 21313.200] (II) Axis 0 value 5735 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 24376.036] (II) Axis 0 value 5676 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 27376.140] (II) Axis 0 value 5709 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 30414.141] (II) Axis 0 value 5735 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 33417.816] (II) Axis 0 value 5690 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 36667.483] (II) Axis 0 value 5734 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 39744.539] (II) Axis 0 value 5734 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 42766.209] (II) Axis 0 value 5734 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 45778.755] (II) Axis 0 value 5694 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 48278.438] (EE) event7  - SynPS/2 Synaptics TouchPad: kernel bug: Touch jump detected and discarded.

See https://wayland.freedesktop.org/libinput/doc/1.10.7/touchpad_jumping_cursor.html for details

[ 48784.856] (II) Axis 0 value 5735 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 51784.872] (II) Axis 0 value 5703 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 54811.682] (II) Axis 0 value 5734 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 58230.760] (II) Axis 0 value 5682 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 61261.452] (II) Axis 0 value 5723 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 61272.861] (EE) event7  - SynPS/2 Synaptics TouchPad: kernel bug: Touch jump detected and discarded.

See https://wayland.freedesktop.org/libinput/doc/1.10.7/touchpad_jumping_cursor.html for details

[ 64422.113] (II) Axis 0 value 5709 is outside expected range [1271, 5672]

See https://wayland.freedesktop.org/libinput/doc/1.10.7//absolute_coordinate_ranges.html for details

[ 66573.529] (EE) event7  - SynPS/2 Synaptics TouchPad: kernel bug: Touch jump detected and discarded.

See https://wayland.freedesktop.org/libinput/doc/1.10.7/touchpad_jumping_cursor.html for details
```

I don't know what to make of these. My touchpad seems to be working fine since the last reboot, and I haven't noticed any issues. I don't think I have changed or specified any coordinates anywhere. But that mention of kernel bug makes me a bit jumpy.

----------

## josephg

i changed libinput to evdev in /etc/portage/make.conf, and all issues seem to have disappeared.

```
INPUT_DEVICES="evdev synaptics"
```

no more kernel bug about touch jump, and i don't think my touchpad is multitouch.

my ranges are correctly identified as well.

so much trying to keep up with bleeding edge  :Sad:  i think i'm quite happy to trail behind, and rather be stable.

----------

## khayyam

 *josephg wrote:*   

> so much trying to keep up with bleeding edge :( i think i'm quite happy to trail behind, and rather be stable.

 

josephg ... it's not considered bleeding edge upstream ("this driver can be used as as drop-in replacement for evdev and synaptics") ... it's the new broken.

best ... khay

----------

## josephg

I thought Gentoo changed from evdev/synaptics to libinput sometime ago.

----------

