Bug: hid-xinmo: Both joysticks register as player 1

[Anthony Agresta <me@anthonyagresta.com>]

Hi folks.

I recently upgraded from 3.17.6-1 -> 4.1.6-1, and my joystick stopped
working correctly.
I'm using some admittedly poorly-behaved hardware, with the hid-xinmo driver.

The hardware is a dual-joystick + 22-button USB controller, for use in
a MAME cabinet:
http://www.hollandcomputers.com/store/pc/Arcade-Game-Controller-USB-Interface-PCB-Kit-for-PC-MAME-PS3-to-Mame-2517p6687.htm

On the current hid-input driver, both joysticks control player 1's X
and Y axes, which is no good.

I commented out these lines in /drivers/hid/hid-input.c (around line
619) and it solved my problem:

    case HID_GD_RX: case HID_GD_RY: case HID_GD_RZ:
        /* if (field->flags & HID_MAIN_ITEM_RELATIVE)
            map_rel(usage->hid & 0xf);
        else
            map_abs_clear(usage->hid & 0xf);
        break; */

These were added in commit # 79346d620e9de87912de73337f6df8b7f9a46888 ,
to fix a quirk of an Atmel 840B digitizer by forcing the axes to the
first X and Y.
Unfortunately it looks like it has broken my device.

I'm content to run with a patched kernel for my own personal use,
but it might be good to figure out another way to work around the
Atmel 840B's quirk
without breaking the Xin-Mo dual joystick adapter.

I'm not super familiar with the driver, so I don't have a patch
prepared at the moment.
Please let me know if any further information would be useful.

Thanks,

Anthony Agresta