Linux: Chromium misremaps Xbox Series axes and triggers for virtual 045e:0b13 device

Environment

• Host OS: Linux
• Virtual controller provider: libvirtualhid through Sunshine
• Profile: Xbox Series
• Browser: Chromium
• Reported identity: Sunshine (libvirtualhid) X-Box Series Controller (STANDARD GAMEPAD Vendor: 045e Product: 0b13)
• Tester: https://app.lizardbyte.dev/gamepad-tester/

Observed behavior

Chromium applies the following incorrect routes:

• LT controls right-stick X.
• RT controls LT.
• Right-stick Y controls RT.
• Right-stick X controls right-stick Y.

The same controller works correctly in Steam's controller tester. Firefox does not show this axis/trigger routing failure.

Source-level explanation

The Linux uinput backend deliberately presents the Xbox Series profile as Bluetooth 045e:0b13, while emitting canonical Linux/XInput-style axes:

• ABS_X, ABS_Y
• ABS_RX, ABS_RY
• ABS_Z, ABS_RZ

Chromium selects its physical Xbox Series Bluetooth mapper for 045e:0b13. That mapper expects the physical Bluetooth joydev ordering rather than the ordering produced by the virtual uinput device. The reported four misroutes correspond directly to that mismatch.

Chromium source:
https://chromium.googlesource.com/chromium/src/+/HEAD/device/gamepad/gamepad_standard_mappings_linux.cc

Expected behavior

Chromium should expose standard Gamepad API controls with:

• LT and RT on buttons 6 and 7.
• Right-stick X/Y on axes 2 and 3.
• Share on button 17.

Constraints

Steam compatibility is the priority and currently works. Do not reorder the Linux backend's emitted axes merely to satisfy Chromium without proving Steam and Firefox remain correct. Evaluate a consumer-safe transport identity or an exact browser/tester normalization path. Keep Windows behavior unchanged.