USB touch screen not detected inside Docker container (no physical input devices in xinput)

[irislinxx-ops]

Bug: USB touch screen not detected in Docker container (RPi 4 / HAOS)

Description

USB capacitive touch screen (7" 1024x600 HDMI LCD) works on the host but is not accessible inside the HAOSKiosk Docker container. xinput list shows only virtual core devices — no physical input devices at all.

Hardware

• Raspberry Pi 4 (4GB)
• 7" HDMI LCD with USB Capacitive Touch (1024x600, rev2.1)
• Home Assistant OS 2026.6.1 (kernel 6.12.75-haos-raspi)
• HAOS Kiosk Display v1.3.2

Steps to Reproduce

1. Install HAOS Kiosk Display add-on (1.3.2)
2. Configure with HA credentials and dashboard URL
3. Start the add-on on a RPi 4 with a USB touch screen attached
4. Check input devices with xinput list

Expected Behavior

USB touch screen should appear in xinput list and work as a touch input device.

Actual Behavior

xinput list shows only:

⎡ Virtual core pointer                    id=2
⎜   ↳ Virtual core XTEST pointer          id=4
⎣ Virtual core keyboard                   id=3
    ↳ Virtual core XTEST keyboard         id=5

No physical input devices are visible. The touch screen is connected and works on the HAOS host itself, but the Docker container does not receive the input events.

Add-on Configuration

devices:
  - /dev/input/event0 through /dev/input/event25  (mapped in config.yaml)
usb: true
privileged:
  - SYS_ADMIN
map_touch_inputs: true

Despite these mappings, no /dev/input/event* devices are functional inside the container.

Full Log Snippet

xinput list:
  ⎡ Virtual core pointer                    id=2 [master pointer  (3)]
  ⎜   ↳ Virtual core XTEST pointer          id=4 [slave  pointer  (2)]
  ⎣ Virtual core keyboard                   id=3 [master keyboard (2)]
      ↳ Virtual core XTEST keyboard         id=5 [slave  keyboard (3)]

Additional Notes

• VNC (x11vnc) also fails: starts but immediately causes the container to exit with mknod: /dev/tty0: File exists
• This is on a Pi 4 with vc4-fkms-v3d display driver
• The same USB touch screen works fine when connected to standard Linux (Ubuntu, RPi OS)

[puterboy]

Seems like Alpine Linux is not recognizing your LCD.
Can you try another HDMI display to test?
Would be helpful to see the full logs rather than just snippets.

[irislinxx-ops]

Hi puterboy, Thanks for the response. Unfortunately we don't have another HDMI display available to test with at the moment — this is the only touch screen we have. Per your request, here are the full diagnostic details: Container Environment: - HAOS Kiosk Display v1.3.2 on HAOS 2026.6.1 - RPi 4 (4GB), kernel 6.12.75-haos-raspi - Display driver: vc4-fkms-v3d Key Diagnostics: - /dev/input/event* and /dev/input/mouse0 are mapped in config.yaml but non-functional inside container - Host detects the touchscreen at /dev/input/event0 and /dev/input/mouse0 - xinput list inside container shows only virtual core devices (IDs 2-5) — no physical input devices - ls -la /dev/input/ inside container shows event devices exist but produce no events - full_access: true crashes the container entirely (X11 conflict with --privileged mode) - VNC also fails with: mknod: /dev/tty0: File exists Known limitation: the rad845/HAOS-kiosk-mod fork is x86-64 only, not ARM-compatible, so that's not an option for RPi 4. Happy to run any specific diagnostic commands you suggest. Thanks for looking into this. — Iris

[puterboy]

Still not seeing full logs.
Also please show full output for your key dianostics.
Thanks