Can't grab/release keyboard and mouse, but can release

[rolandog]

According to the ReadMe:

Press Ctrl + Raspberry to grab/release your keyboard and mouse, switching between local use and USB.

Press Ctrl + Shift + Raspberry (on the grabbed keyboard) to exit.

However, Ctrl + Raspberry doesn't seem to grab/release the keyboard (Ctrl + Shift + Raspberry works fine, though).

I'll document my debugging journey to get the main branch working after compiling and installing (may help #39):

• added libcomposite to /etc/modules (echo 'libcomposite' | sudo tee -a /etc/modules, as commented on readme: Autorun example #19 ), and rebooted
• HOOK_PATH is hard-coded to /home/pi/pi400kb/hook.sh on pi400.h and on CMakeLists.txt; updated and re-compiled.
• LED path may be outdated for Bullseye (replaced /sys/class/leds/led0/trigger and /sys/class/leds/led0/brightness to /sys/class/leds/PWR/trigger and /sys/class/leds/PWR/brightness, respectively, in hook.sh).
• Manually inspected the Keyboard and Mouse variables passed to CMake and manually passed them when building: cmake .. -DMOUSE_DEV="/dev/input/by-id/usb-PixArt_USB_Optical_Mouse-event-mouse" -DMOUSE_VID=0x093a -DMOUSE_PID=0x2510 -DKEYBOARD_DEV="/dev/input/by-id/usb-_Raspberry_Pi_Internal_Keyboard-event-kbd" -DKEYBOARD_VID=0x04d9 -DKEYBOARD_PID=0x0007

I have tried:

• creating a shortcut to manually restart the service (doesn't work?) in /etc/xdg/openbox/lxde-pi-rc.xml (though I'm not sure if C-W is the right combination for Ctrl + Raspberry).

  <keyboard>
    <!-- 
         [... default commands ...]
    -->
    <!-- My Custom Keyboard Shortcuts -->
    <keybind key="C-W">
      <action name="Execute">
        <command>sudo systemctl restart pi400kb.service</command>
      </action>
    </keybind>
  </keyboard>

• Manually inspected the pi400kb.service logs (journalctl -f -u pi400kb.service), and found the following error message:

Jun 12 14:33:53 pi systemd[1]: Started pi400kb USB OTG Keyboard & Mouse forwarding.
Jun 12 14:33:53 pi pi400kb[2515]: usbg_create_gadget()  duplicate gadget name
Jun 12 14:33:53 pi pi400kb[2515]:  
Jun 12 14:33:53 pi pi400kb[2515]: Error creating gadget
Jun 12 14:33:53 pi pi400kb[2515]: Error: USBG_ERROR_EXIST : Already exist
Jun 12 14:33:54 pi pi400kb[2515]: Found keyboard at: /dev/hidraw1
Jun 12 14:33:54 pi pi400kb[2515]: Found mouse at: /dev/hidraw0
Jun 12 14:33:54 pi pi400kb[2515]: Grabbing Keyboard and/or Mouse
Jun 12 14:33:54 pi pi400kb[2515]: Grabbing: /dev/input/by-id/usb-_Raspberry_Pi_Internal_Keyboard-event-kbd
Jun 12 14:33:54 pi pi400kb[2515]: Grabbing: /dev/input/by-id/usb-PixArt_USB_Optical_Mouse-event-mouse
Jun 12 14:33:54 pi pi400kb[2515]: Running...
Jun 12 14:33:54 pi pi400kb[2515]: K:1 0 0 0 0 0 0 0
Jun 12 14:33:54 pi pi400kb[2515]: K:9 0 0 0 0 0 0 0
Jun 12 14:33:54 pi pi400kb[2515]: Releasing Keyboard and/or Mouse
Jun 12 14:33:54 pi pi400kb[2515]: K:b 0 0 0 0 0 0 0
Jun 12 14:33:54 pi pi400kb[2515]: Releasing Keyboard and/or Mouse
Jun 12 14:33:54 pi pi400kb[2515]: Cleanup USB
Jun 12 14:33:54 pi systemd[1]: pi400kb.service: Succeeded.

I'm not knowledgeable in C, so that's the limit to my ability to debug (and I'm unsure if the problem may be on pi400kb's gadget-hid.c:

pi400kb/gadget-hid.c

Line 120 in ad102c2

usbg_ret = usbg_create_gadget(s, "g1", &g_attrs, &g_strs, &g);

... or the usbg_create_gadget function from libusbgx:

https://github.com/linux-usb-gadgets/libusbgx/blob/721e3a1cbd7e2b6361bb439d3959e7403e4f0092/src/usbg.c#L1531

I'd like to help in getting it to work... so, please let me know what I can do to continue debugging.

[Gadgetoid]

It's been a long time since I used/worked on this, so I'll have to get up to speed first. The Gadget HID stuff might be a red-herring.