Re: detecting when keys are being pressed on a keyboard

Jiri Kosina <[email protected]>
Newsgroups gmane.linux.usb.devel,gmane.linux.kernel.input
Message-ID <[email protected]>
On Mon, 24 Sep 2007, Oliver Neukum wrote:

> > HID doesn't keep any permanent state by itself. If you want to know 
> > whether a given key is currently pressed or not, you'd have to inspect 
> > the bitfields inside input_dev*, I am afraid.
> I see no way to do this without a race condition. The field isn't locked
> as far as I can tell.

Hi Oliver,

Dmitry (CC added) has been doing a lot of rework of locking in input as 
far as I know. He would know this better.

> Secondly, what is to happen in case of a system wide suspend? Will
> the system wake up thinking that the key is still pressed?

If the release event didn't happen before the machine went to suspend, I'd 
say so.

-- 
Jiri Kosina

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