Re: input: evdev.c EVIOCGRAB semantics question

[Ian Stirling <ian.stirling@mauve.plus.com>]

Dmitry Torokhov wrote:
> On 8/14/06, Zephaniah E. Hull <warp@aehallh.com> wrote:
>> On Mon, Aug 14, 2006 at 10:20:09AM -0400, Dmitry Torokhov wrote:
>> >

>> xf86-input-evdev will more or less happily continue talking to a mouse
>> that it can't grab, however things become somewhat more problematic when
>> it comes to keyboards.
>>
>> X needs to keep the keyboard driver from receiving events while it has
>> it open
> 
> Keyboard... can't X just ignore data from old keyboard driver while
> evdev-based keyboard driver is used?

Apart from the other issues, it'd be nice to be able to have some way to 
disable 'keyboards'.

For example, I have some CM108 based audio USB cards, which come with 3 
(event generating) keys. These generate events for F13,F14,'help'.
Of course I can do something in my X wm config to get them to do stuff - 
but this is hardly ideal, especially for headless machines, or whatever.
And it utterly breaks if I want to distinguish between 'F13' being 
pressed on the audio device in the kitchen, and the one in the lounge, 
or I want to stop X.
evdev works just fine for this. I'd love to have some way to say 'this 
should never be a core keyboard' - and have it generate no keyboard
events, only output stuff on evdev. As another example - I might like to 
have an unsecured keyboard, to which I can point X - but I never want it 
to allow magic sysrq, or to generate console events if the system isn't 
running X.

The lack of unique per-device IDs is of course really annoying in this case.