Re: [PATCH] Input: Support for a less exclusive grab.

From: Dmitry Torokhov
Date: Tue Jun 12 2007 - 01:07:27 EST

Hi Zephaniah,

On Saturday 09 June 2007 04:48, Zephaniah E. Hull wrote:
> EVIOCGRAB is nice and very useful, however over time I've gotten
> multiple requests to make it possible for applications to get events
> straight from the event device while xf86-input-evdev is getting events
> from the same device.
> Here is the least invasive patch I could think of, it changes the
> behavior of EVIOCGRAB in some cases, specificly behavior is identical if
> the argument is 0 or 1, however if the argument is true and != 1, then
> it does a 'non exclusive grab', a better name might be handy.
> What this does is allow the events to go to everything that's using
> evdev to get events, but grabs it from anything else. ÂAbout as close to
> what people want as I can get, and fairly non-invasive.

Unfortunately this also robs non-legacy input handlers (such as
rfkill-input) of input events. Does xf86-input-evdev really needs to
grab devices exclusively? I guess we can't abandon the standard
keyboard driver until X supports hotplugging. How close is it to
support devices coming and going?

If we can't remain as is until X hotplug is ready then I'd rather had
a separate ioctl that disables legacy input handlers (keyboard, mousedev)
for a given input device.

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