SONiX GK630: Backspace repeats continuously after a single keypress on X11

Distribution

Linux Mint 22.3 Cinnamon (Zena)

Package version

6.6.9

Graphics hardware in use

NVIDIA GeForce RTX 3060 (driver 595.84)

Frequency

Always

Bug description

Problem

On Linux Mint 22.3 Cinnamon with a SONiX GK630 Gaming Keyboard, pressing Backspace once causes Backspace to repeat continuously and delete text backwards, even though the key is NOT physically held down.

This happens on X11.

The problem was reproduced by pressing Backspace only once.

Observed behavior

After a single physical Backspace keypress, X11 starts generating repeated Backspace events continuously.

The keyboard itself is not stuck and the key is not being held down.

The same keyboard works correctly under Windows.

Diagnostics

Keyboard is exposed as two XInput devices:

• ID 9: /dev/input/event6
• ID 19: /dev/input/event7

Both identify as:

SONiX GK630 Gaming Keyboard

Both report Device Enabled: 1.

XInput feedback for both devices reports:

global_auto_repeat is 1

The relevant XInput device (ID 19) was producing repeated key events after a single Backspace press.

Workaround

Disabling XInput device ID 19 fixes the problem immediately:

xinput disable 19

After disabling device 19, Backspace works normally.

Re-enabling it brings the problem back.

No physical key was held down during the reproduction.

Environment

• Linux Mint 22.3 Cinnamon (Zena)
• Cinnamon 6.6.9
• X11 / X.Org 21.1.11
• Kernel 7.0.0-30-generic
• NVIDIA GeForce RTX 3060
• NVIDIA driver 595.84
• SONiX GK630 Gaming Keyboard

Steps to reproduce

1. Boot Linux Mint Cinnamon and log into an X11 session.
2. Connect a SONiX GK630 Gaming Keyboard.
3. Open any application where text can be entered.
4. Press the Backspace key once and release it immediately.
5. Observe that Backspace continues repeating automatically, deleting text backwards, even though the key is no longer being held.
6. The issue can be reproduced consistently.
7. Running xinput test 19 shows repeated key events after a single physical key press.

Expected behavior

Pressing and releasing Backspace once should delete exactly one character. Backspace should only repeat while the key is physically held down.

Additional information

System

• Linux Mint 22.3 Cinnamon (Zena)
• X11 session
• Kernel: 7.0.0-30-generic
• Keyboard: SONiX GK630 Gaming Keyboard

Problem

After pressing Backspace only once, Backspace starts repeating continuously and deletes text backwards without holding the key down.

The problem occurs on X11.

The important detail is that this is NOT a physically held key.

With:

xinput test 19

a single physical Backspace press produces repeated events such as:

key press 248
key release 248
key press 248
key release 248
...

The key continues repeating even though the physical key was pressed only once.

XInput devices

The keyboard creates two XInput keyboard interfaces:

ID 9  -> /dev/input/event6
ID 19 -> /dev/input/event7

Both are reported as:

SONiX GK630 Gaming Keyboard

Both are enabled by default.

Workaround

Disabling XInput device 19 immediately fixes the problem:

xinput disable 19

After disabling device 19, Backspace works normally and does not repeat.

Re-enabling it with:

xinput enable 19

brings the problem back.

This strongly suggests that the second XInput interface (/dev/input/event7, XInput ID 19) is involved in the problem.

Additional observations

The keyboard works correctly in Windows.

The problem persists after upgrading from kernel 7.0.0-29 to 7.0.0-30.

The X11 keyboard auto-repeat setting itself is normal.

The issue appears to be related to the duplicate/second SONiX GK630 XInput keyboard interface rather than a physically stuck key.

Temporary workaround

xinput disable 19

This makes the keyboard fully usable under X11, including Backspace.

Start by reproducing the issue with xinput test 19 and compare the two SONiX GK630 interfaces, /dev/input/event6 and /dev/input/event7. Done means a single Backspace press produces one deletion and repeated events no longer occur without disabling XInput device 19.