Re: [Patch-V2 1/6] INPUT: xpad: Add minimal support for Logitech G920 Wheel

From: Michal Malý
Date: Thu Jan 07 2016 - 18:05:25 EST


On Thu, 2016-01-07 at 14:53 -0800, Dmitry Torokhov wrote:
> On Thu, Jan 7, 2016 at 2:50 PM, Michal MalÃ
> <madcatxster@xxxxxxxxxxxxxxxxxx> wrote:
> > On Wed, 2016-01-06 at 17:47 -0800, Dmitry Torokhov wrote:
> > > On Wed, Jan 06, 2016 at 03:36:57PM +0100, Jiri Kosina wrote:
> > > > On Mon, 4 Jan 2016, Benjamin Tissoires wrote:
> > > >
> > > > > Jiri, I *think* this commit still is in your next pull
> > > > > request
> > > > > for
> > > > > Linus. We might want to drop it before it hits Linus' tree.
> > > >
> > > > What exactly would be the reasoning for dropping it?
> > >
> > > It is wrong. Aside form the fact that IMO xpad.c is the wrong
> > > place
> > > for
> > > this code to be in, why are we waiting for the input device to be
> > > opened by userspace before we do the switch instead of doing it
> > > immediately?
> > >
> >
> > Hi all,
> >
> > I have to disagree with the xpad driver being the wrong place to
> > handle
> > this. The xpad driver matches devices it should handle by interface
> > class, subclass and protocol. When G920 first appears on the USB
> > bus,
> > it for all intents and purposes looks like a Xbox One controller so
> > the
> > xpad driver picks it up even if there is no G920-specific code in
> > the
> > driver. Unless there is a way how to blacklist certain idProduct
> > values, the switch from XBone mode to HID mode will have to be done
> > in
> > the xpad driver.
> >
> > I'm pretty much done with the simple switching module but it will
> > be of
> > no use if we cannot make the xpad module ignore G920 first.
>
> I see that Simon's patch added:
>
> XPAD_XBOXONE_VENDOR(0x046d),
>
> to the xpad driver. Are you saying that we latch onto the controller
> even without this addition?
>
> Thanks.

Sorry, my bad, I missed that change in the patch. Handling the switch
elsewhere should be no problem then.

Michal