Gamepad focus model (Re: Input and games.)

[Daniel Stone]

Hi,

On 13 May 2013 14:43, Todd Showalter <todd at electronjump.com> wrote:
> On Mon, May 13, 2013 at 2:33 AM, David Herrmann <dh.herrmann at gmail.com> wrote:
>> That is why the kernel provides "PHYS" and "UNIQ" fields for every
>> input device (they might be empty if not implemented, but at least
>> they're supposed to be there..). "PHYS" provides the physical location
>> for the device. "UNIQ" provides a unique identification.
>
>     PHYS is potentially useful, but not reliable; there are often
> several USB ports near each other, and the player may not re-plug the
> device in the same one, especially if they are on the back of the
> machine.  With wireless setups we can't be sure that PHYS will be
> identical between connections.  Still, it's useful as a hint.
>
>     UNIQ has been an empty string on every USB input device I've
> encountered.  I need to get bluetooth set up (my PC has no bluetooth
> hardware, I need to buy a card or something), so i can't say whether
> wireless devices provide useful UNIQ values.

Yep, it's a difficult problem, and no-one tends to fill out UNIQ or
any of the serial number fields because it makes production more
expensive and complicated.  Same reason EDID is really badly flawed.
But it's totally orthogonal to the protocol discussion ...

Cheers,
Daniel