[rcore] Touch/Input not detected after kernel update

[JesperNaarttijarvi]

[Bug] Touch/Input Not Detected by Raylib After Kernel Update

Description:
After updating the Raspberry Pi kernel, Raylib no longer detects touch/input events. Verified using custom logging and Raylib's core_input examples. The issue persists even after a fresh Raylib installation.

I have only tested with our touch input, and not verified if it the same problem with a mouse or other touch pads.

System Details:

• Hardware: Raspberry Pi CM4
• OS: Debian GNU/Linux 12 (bookworm), Lite

PRETTY_NAME="Debian GNU/Linux 12 (bookworm)"
NAME="Debian GNU/Linux"
VERSION_ID="12"
VERSION="12 (bookworm)"
VERSION_CODENAME=bookworm
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"

Kernel Update Details:
Issue started after performing the following kernel updates:

sudo apt-get install build-essential
...
...
Upgraded packages:
linux-headers-rpi-2712 linux-headers-rpi-v8 linux-image-rpi-2712 linux-image-rpi-v8

Newly installed:
linux-headers-6.12.25+rpt-common-rpi
linux-image-6.12.25+rpt-rpi-2712
linux-kbuild-6.12.25+rpt
linux-headers-6.12.25+rpt-rpi-2712
linux-image-6.12.25+rpt-rpi-v8
linux-headers-6.12.25+rpt-rpi-v8

Issue Verification:

• evtest confirms touch input is detected:

evtest /dev/input/event0
Input device name: "ILITEK ILITEK-TP"
Supported events:
Event type 1 (EV_KEY), Event code 330 (BTN_TOUCH)
Event type 3 (EV_ABS), Event codes 0 (ABS_X), 1 (ABS_Y), 53 (ABS_MT_POSITION_X), 54 (ABS_MT_POSITION_Y), 57 (ABS_MT_TRACKING_ID)
Event type 4 (EV_MSC), Event code 5 (MSC_TIMESTAMP)

Sample evtest Output:

Event: time 1746805905.148705, type 1 (EV_KEY), code 330 (BTN_TOUCH), value 1
Event: time 1746805905.148705, type 3 (EV_ABS), code 0 (ABS_X), value 5296
Event: time 1746805905.148705, type 3 (EV_ABS), code 1 (ABS_Y), value 5644
...

However, Raylib examples and applications do not react to these input events.

Expected Behavior:
Raylib should detect and handle touch/input events as previously.

Actual Behavior:
No touch/input events are detected by Raylib.

Steps to Reproduce:

1. Update Raspberry Pi kernel to 6.12.25+rpt-rpi-v8.
2. Run Raylib's core input examples or custom input logging applications.

Additional Information:

• The issue started specifically after updating to kernel version 6.12.25+rpt-rpi-v8.
• Evtest logs indicate the input hardware functions correctly, suggesting a compatibility issue between Raylib and the updated kernel.

Request:
Guidance or a fix to restore Raylib input functionality.

[JesperNaarttijarvi]

I investigated this problem today, specifically around how DRM handles input devices. Please note I'm not experienced with C, so my observations could be incorrect.

The issue seems related to how Raylib manages multiple input devices. Currently, Raylib only supports a single input device per type (mouse/touch). More details on this limitation are discussed here: [Raylib issue #4631](#4631).

Raylib detects several input devices:

test@test:~/raylibTest $ evtest
Available devices:
/dev/input/event0:      ILITEK ILITEK-TP
/dev/input/event1:      ILITEK ILITEK-TP Mouse
/dev/input/event2:      vc4-hdmi-0
/dev/input/event3:      vc4-hdmi-0 HDMI Jack
/dev/input/event4:      vc4-hdmi-1
/dev/input/event5:      vc4-hdmi-1 HDMI Jack

Initially, /dev/input/event0 is recognized and used by Raylib. Later, /dev/input/event1 is discovered and incorrectly replaces the original device. However, /dev/input/event1 doesn't provide user input, which explains why input events appear to stop working.

Temporary Fix

I temporarily resolved the issue by modifying the ConfigureEvdevDevice function in rcore_drm.c:

// If a device is already configured, ignore any subsequent devices
if (platform.mouseFd != -1) {
    //close(platform.mouseFd); // Old behavior

    TRACELOG(LOG_WARNING, "CONFIG: Already have mouseFd=%d. Ignoring new device (fd=%d).", platform.mouseFd, fd);
    close(fd);
    return;
}

Permanent solution

Write a script that permanently disables incorrect input to be visible for raylib, and avoid this problem.

Something like this in the udev rules

# Udev rule to ignore ILITEK "mouse" interface
KERNEL=="event*", SUBSYSTEM=="input",   ENV{ID_VENDOR_ID}=="222a",   ENV{ID_MODEL_ID}=="0001",   ENV{ID_INPUT_MOUSE>

Relevant Logs

Customized logging from rcore_drm.c during initialization and polling:

INFO: Initializing raylib 5.6-dev
INFO: Platform backend: NATIVE DRM
INFO: Supported raylib modules:
INFO:     > rcore:..... loaded (mandatory)
INFO:     > rlgl:...... loaded (mandatory)
INFO:     > rshapes:... loaded (optional)
INFO:     > rtextures:. loaded (optional)
INFO:     > rtext:..... loaded (optional)
INFO:     > rmodels:... loaded (optional)
INFO:     > raudio:.... loaded (optional)
WARNING: DISPLAY: No graphic card set, trying platform-gpu-card
INFO: DISPLAY: platform-gpu-card opened successfully
INFO: DISPLAY: Selected DRM connector mode 2560x1600 (2560x1600p@50)
INFO: DISPLAY: Upscaling required: Screen size (800x450) smaller than display size (2560x1600)
INFO: DISPLAY: Device initialized successfully
INFO:     > Display size: 2560 x 1600
INFO:     > Screen size:  800 x 450
INFO:     > Render size:  800 x 450
INFO:     > Viewport offsets: 0, 50
WARNING: GetCurrentMonitor() not implemented on target platform
WARNING: GetCurrentMonitor() not implemented on target platform
WARNING: SetWindowPosition() not available on target platform
INFO: GL: Supported extensions count: 117
INFO: GL: OpenGL device information:
INFO:     > Vendor:   Broadcom
INFO:     > Renderer: V3D 4.2.14.0
INFO:     > Version:  OpenGL ES 3.1 Mesa 24.2.8-1~bpo12+rpt2
INFO:     > GLSL:     OpenGL ES GLSL ES 3.10
INFO: GL: VAO extension detected, VAO functions loaded successfully
INFO: GL: NPOT textures extension detected, full NPOT textures supported
INFO: GL: DXT compressed textures supported
INFO: GL: ETC1 compressed textures supported
[RCORE] InitEvdevInput(): scanning /dev/input ...
[RCORE] InitEvdevInput(): found device => /dev/input/event5
INFO: CONFIG: Attempting to open device: /dev/input/event5
INFO: CONFIG: Opened device '/dev/input/event5' successfully (fd=9). Checking capabilities...
INFO: CONFIG: Device '/dev/input/event5' => isKeyboard=0, isMouse=0, isTouch=0, isGamepad=0, absAxisCount=0
INFO: CONFIG: Device '/dev/input/event5' not needed or limit reached. Closing fd=9.
[RCORE] InitEvdevInput(): found device => /dev/input/event4
INFO: CONFIG: Attempting to open device: /dev/input/event4
INFO: CONFIG: Opened device '/dev/input/event4' successfully (fd=9). Checking capabilities...
INFO: CONFIG: Device '/dev/input/event4' => isKeyboard=0, isMouse=0, isTouch=0, isGamepad=0, absAxisCount=0
INFO: CONFIG: Device '/dev/input/event4' not needed or limit reached. Closing fd=9.
[RCORE] InitEvdevInput(): found device => /dev/input/event3
INFO: CONFIG: Attempting to open device: /dev/input/event3
INFO: CONFIG: Opened device '/dev/input/event3' successfully (fd=9). Checking capabilities...
INFO: CONFIG: Device '/dev/input/event3' => isKeyboard=0, isMouse=0, isTouch=0, isGamepad=0, absAxisCount=0
INFO: CONFIG: Device '/dev/input/event3' not needed or limit reached. Closing fd=9.
[RCORE] InitEvdevInput(): found device => /dev/input/event2
INFO: CONFIG: Attempting to open device: /dev/input/event2
INFO: CONFIG: Opened device '/dev/input/event2' successfully (fd=9). Checking capabilities...
INFO: CONFIG: Device '/dev/input/event2' => isKeyboard=0, isMouse=0, isTouch=0, isGamepad=0, absAxisCount=0
INFO: CONFIG: Device '/dev/input/event2' not needed or limit reached. Closing fd=9.
[RCORE] InitEvdevInput(): found device => /dev/input/event0
INFO: CONFIG: Attempting to open device: /dev/input/event0
INFO: CONFIG: Opened device '/dev/input/event0' successfully (fd=9). Checking capabilities...
INFO: CONFIG: Device '/dev/input/event0' => isKeyboard=0, isMouse=0, isTouch=1, isGamepad=0, absAxisCount=2
INFO: INPUT: Initialized input device '/dev/input/event0' as mouse/touch (fd=9)
[RCORE] InitEvdevInput(): found device => /dev/input/mouse0
INFO: CONFIG: Attempting to open device: /dev/input/mouse0
INFO: CONFIG: Opened device '/dev/input/mouse0' successfully (fd=10). Checking capabilities...
INFO: CONFIG: Device '/dev/input/mouse0' => isKeyboard=0, isMouse=0, isTouch=0, isGamepad=0, absAxisCount=0
INFO: CONFIG: Device '/dev/input/mouse0' not needed or limit reached. Closing fd=10.
[RCORE] InitEvdevInput(): found device => /dev/input/event1
INFO: CONFIG: Attempting to open device: /dev/input/event1
INFO: CONFIG: Opened device '/dev/input/event1' successfully (fd=10). Checking capabilities...
INFO: CONFIG: Device '/dev/input/event1' => isKeyboard=0, isMouse=1, isTouch=0, isGamepad=0, absAxisCount=2
**INFO: CONFIG: Replacing existing mouseFd (fd=9) with new device (fd=10). Closing old fd...**
INFO: INPUT: Initialized input device '/dev/input/event1' as mouse/touch (fd=10)
[RCORE] InitEvdevInput(): found device => /dev/input/mouse1
INFO: CONFIG: Attempting to open device: /dev/input/mouse1
INFO: CONFIG: Opened device '/dev/input/mouse1' successfully (fd=9). Checking capabilities...
INFO: CONFIG: Device '/dev/input/mouse1' => isKeyboard=0, isMouse=0, isTouch=0, isGamepad=0, absAxisCount=0
INFO: CONFIG: Device '/dev/input/mouse1' not needed or limit reached. Closing fd=9.
[RCORE] InitEvdevInput(): finished scanning /dev/input
....
INFO: PLATFORM: DRM: Initialized successfully
INFO: TEXTURE: [ID 1] Texture loaded successfully (1x1 | R8G8B8A8 | 1 mipmaps)
INFO: TEXTURE: [ID 1] Default texture loaded successfully
INFO: SHADER: [ID 1] Vertex shader compiled successfully
INFO: SHADER: [ID 2] Fragment shader compiled successfully
INFO: SHADER: [ID 3] Program shader loaded successfully
INFO: SHADER: [ID 3] Default shader loaded successfully
INFO: RLGL: Render batch vertex buffers loaded successfully in RAM (CPU)
INFO: RLGL: Render batch vertex buffers loaded successfully in VRAM (GPU)
INFO: RLGL: Default OpenGL state initialized successfully
INFO: TEXTURE: [ID 2] Texture loaded successfully (128x128 | GRAY_ALPHA | 1 mipmaps)
INFO: FONT: Default font loaded successfully (224 glyphs)
INFO: SYSTEM: Working Directory: /home/itos/raylibTest/raylib/examples/core
INFO: TIMER: Target time per frame: 16.667 milliseconds
....
[RCORE] PollMouseEvents() => fd=10
[RCORE] PollMouseEvents() => Entering while loop...
[RCORE] PollMouseEvents() => read() returned -1
, errno=11 (Resource temporarily unavailable)
[RCORE] PollMouseEvents() => Exiting while loop
[RCORE] PollMouseEvents() => fd=10
[RCORE] PollMouseEvents() => Entering while loop...
[RCORE] PollMouseEvents() => read() returned -1
, errno=11 (Resource temporarily unavailable)