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

From: Dmitry Torokhov
Date: Thu Jan 07 2016 - 17:53:18 EST


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.

--
Dmitry