Re: drivers/input/input.c and a broken USB HID Contour ShuttlePRO v2

[Greg KH <gregkh@linuxfoundation.org>]

On Sun, Mar 09, 2014 at 04:55:32PM +0100, Harald Albrecht wrote:
> I would like to improve support for the multimedia controllers from 
> Contour company, as there currently get relative events swalled by input.c.
> 
> The background: Contour seems to have messed up the USB HID descriptions 
> of their multimedia controller devices in that these report to use 
> relative axis when in fact they are creating EV_REL events with absolute 
> coordinate values. The problem here is, that mapping these events to 
> EV_ABS will break all existing software that supports these devices.
> 
> Unfortunately, drivers/input/input.c correctly swallows any relative 
> events with a relative movement value of zero...
> 
>     case EV_REL:
>        if (is_event_supported(code, dev->relbit, REL_MAX) && value)
>          disposition = INPUT_PASS_TO_HANDLERS;
>        break;
> 
> Simply removing the "&& value" would most probably have adverse effect 
> on many software. Unfortunately, there is yet no "quirks" handling 
> present in input.c.
> 
> How can I add such quirks handling in a way that would be acceptable by 
> the kernel maintainers?

The people on linux-input@vger.kernel.org (now cc:ed) might know more...