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WebNoteId: 3
Title: Issue#3 - Linux Kernel Issue in v4.8 to 4.17

Summary: In Linux kernel version 4.8 to ???, support to control the LEDs on the Delcom USB Visual Indicators was added. This support cause the USB HID event (such as the Keycode, Mouse and Joystick to not work. As well as defaulted the LED PWM values to 0%. This web note describes how to resolve this issue.

Date: Jan 24, 2018   -Updated September 11, 2019
Effects: Linux kernel versions v4.8 to 4.17.
All Delcom USB device with USB VID=0xFC5 and PID=0xB080.

With the release of the Linux Kernel v4.8 driver support was added for the Delcom USB HID Visual Indicator device. This driver (drivers/hid/hid-led.c) allows the user to control the USB light. When this driver was added the Delcom device was also added to the hid_have_special_driver list in hid-quirks.c file. This causes the Delcom device to no longer work as a HID device winch disables the USB HID Keycode, Mouse and Joystick events. The hid-led.c driver also changed the PWM values on the LED ports to zero when the device is opened.

  • RECOMMENED SOLUTION - Change the PID (USB Product Identifier number). This will cause the Linux kernel to not add the HID Visual Indicator support driver and will allow the device to run correctly. Note all software that connects to the device must also use the same PID. To make this change you will need to run the delcomSetPID utility. This utility allows you to switch the PID between OxB080(default) and 0xA080(alterate). Click here for the file delcomSetupPID.
    delcomSetupPID 0xA080

  • Use a kernel driver version lowered than v4.8 or equal to or greater than 4.18.
    • Ubuntu - Use ukuu to update the kernel. Install ukuu. Then run ukuu from the GUI. Select the latest kernel. Reboot. Select latest kernel from GRUB.
         sudo add-apt-repository ppa:teejee2008/ppa
         sudo apt-get update
         sudo apt-get install ukuu
    • Raspbian - Use rpi-update. Note at the time of this writing the fixed kernel has not been release for Raspbian. But is claimed to be released shortly. For now the best solution is to change the PID, see below.
         sudo rpi-update

  • Remove the Delcom device (VID=0x0FC5 and PID=0xB080) from the hid-quirks.c file and delete the drivers/hid/hid-led.c files and recompile the kernel.

Linux kernel links:
Delcom support corrected
Delcom support removed

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