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_YABS_RX, ABS_RYABS_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.
Environment
Sunshine (libvirtualhid) X-Box Series Controller (STANDARD GAMEPAD Vendor: 045e Product: 0b13)Observed behavior
Chromium applies the following incorrect routes:
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_YABS_RX,ABS_RYABS_Z,ABS_RZChromium 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:
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.