Bug Report: Firmware 1.10.1 USB Device Manager breaks HID emulation on hardware KVM switches (ASIX AX68002)

KVM
1

I lost the ability to use my Steetek KVM switch 8 port with keyboard or mouse emulation after upgrading my GL-RM1 Comet to firmware 1.10.1, only downgrading back to 1.9.2 fixed the issue. I spent time troubleshooting the issue with Google Gemini Flash Extended, which suggested a possible reason for the issue and a potential solution so I can go back to using the newest firmware. It wrote the message below detailing its findings:

Summary of Issue: After upgrading to 1.10.1, the Comet's emulated keyboard and mouse stop working when connected to hardware KVM switches that use integrated USB microcontrollers (specifically switches built on the ASIX AX68002 SoC).

Troubleshooting & Verification:

  • Direct Host Connection: The Comet works normally when connected directly to a PC/Mac USB port.

  • Through KVM Switch: The KVM controller drops enumeration completely; no keyboard or mouse packets reach the downstream host.

  • Custom Device Spoofing: Changing the Vendor ID, Product ID, and device strings in the new "Custom Device" modal does not resolve the issue, confirming this is a low-level descriptor/endpoint conflict rather than a VID/PID whitelist issue.

  • Firmware Rollback: Rolling back to firmware 1.10.0 / 1.9.2 immediately restores full keyboard and mouse functionality through the KVM switch.

Root Cause: The updated composite gadget configuration in 1.10.1 bundles endpoints and descriptors in a way that strict, hardware-level KVM host parsers reject. The embedded MCU expects standard USB Boot-Protocol descriptors (Subclass 1, 6KRO) and fails to enumerate the new composite tree.

Requested Fix: Please add a "Legacy / KVM Compatibility Mode" toggle in the Web UI under the USB Device Manager. When enabled, this should force the USB gadget stack to output a strict, standard Boot-Protocol keyboard/mouse descriptor (Subclass 1, 8-byte 6KRO reports) and strip auxiliary endpoints (virtual media, audio/mic) to ensure compatibility with hardware KVM microcontrollers.

3

Hi, thanks for the detailed report and testing. We'll forward this issue to our R&D team for further investigation. Sorry for the inconvenience!

4

Try this firmware and see if it make any differences

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5

Thank you, that worked! HID Emulation restored running V1.10.2 beta1, What was the fix? because i did not have to change any settings after updating.

6

To support Camera/UVC functionality, we have enabled the IAD flag uniformly in the USB Gadget descriptors. However, your KVM Switch has poor compatibility with this IAD descriptor.

7

Thank you for the explanation! Will this fix be carried over into the final v1.10.2 release and future firmware builds?

My setup strictly relies on keyboard and mouse emulation, as auxiliary device descriptors break hotkey switching on my hardware KVM switch. I prefer to keep my device on the latest firmware, so I want to confirm that this fix will remain in mainline releases moving forward.

Thanks again to the team for the incredibly quick turnaround and support!

8

We will do our best to improve the device compatibility, and at the very least, this FIX will be included in RM1.

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