> I was able to get some more information, but as yet have not been able to
>  get time on the real hardware. Attached is a 2nd patch which should
> improve the support, I'll formally submit it next week.... But if anyone
> can test it first that would be great.

Obviously the 'submit next week' never happened... but I now have one of
these wheels to work on. The bad news is that the information we got does
not appear to be complete.

At present the wheel is mis-recognised as a G27 and forced into an
emulation state, it is somewhat usable in that mode.

If we send the 'G29 mode' command the wheel comes back with a device with
2x HID interfaces and that appears to screw up the probe (full log
attached).
--
Sep 28 12:30:33 retrobox kernel: [11079.944056] usb 2-1: new full-speed
USB device number 3 using uhci_hcd
Sep 28 12:30:33 retrobox kernel: [11080.113102] usb 2-1: New USB device
found, idVendor=046d, idProduct=c24f
Sep 28 12:30:33 retrobox kernel: [11080.113113] usb 2-1: New USB device
strings: Mfr=1, Product=2, SerialNumber=0
Sep 28 12:30:33 retrobox kernel: [11080.113120] usb 2-1: Product: G29
Driving Force Racing Wheel
Sep 28 12:30:33 retrobox kernel: [11080.113125] usb 2-1: Manufacturer:
Logitech
Sep 28 12:30:33 retrobox kernel: [11080.124431] input: Logitech G29
Driving Force Racing Wheel as
/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1:1.0/0003:046D:C24F.0002/input/input10
Sep 28 12:30:33 retrobox kernel: [11080.125134] logitech
0003:046D:C24F.0002: input,hidraw0: USB HID v1.11 Joystick [Logitech G29
Driving Force Racing Wheel] on usb-0000:00:1d.0-1/input0
Sep 28 12:30:33 retrobox kernel: [11080.126094] logitech
0003:046D:C24F.0002: Force feedback support for Logitech Gaming Wheels
Sep 28 12:30:33 retrobox kernel: [11080.134307] logitech
0003:046D:C24F.0003: hiddev0,hidraw1: USB HID v1.11 Device [Logitech G29
Driving Force Racing Wheel] on usb-0000:00:1d.0-1/input1
Sep 28 12:30:33 retrobox kernel: [11080.134319] logitech
0003:046D:C24F.0003: not enough values in HID_OUTPUT_REPORT 0 field 0
Sep 28 12:30:33 retrobox kernel: [11080.134339] logitech: probe of
0003:046D:C24F.0003 failed with error -1
--

Any suggestions as to how we can 'ignore' or unbind the 2nd interface in
order to only work with the 1st?
Simon