Re: [PATCH v3 0/7] Support inhibiting input devices

Pavel Machek
2020-06-07T20:24:19Z

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On Fri 2020-06-05 19:33:28, Andrzej Pietrasiewicz wrote:
> Userspace might want to implement a policy to temporarily disregard input
> from certain devices.

Wow, you certainly cc a lot of lists.

> An example use case is a convertible laptop, whose keyboard can be folded
> under the screen to create tablet-like experience. The user then must hold
> the laptop in such a way that it is difficult to avoid pressing the keyboard
> keys. It is therefore desirable to temporarily disregard input from the
> keyboard, until it is folded back. This obviously is a policy which should
> be kept out of the kernel, but the kernel must provide suitable means to
> implement such a policy.
>
> Due to interactions with suspend/resume, a helper has been added for drivers
> to decide if the device is being used or not (PATCH 1/7) and it has been
> applied to relevant drivers (PATCH 2,4,5,6/7).

But is that a right way to implement it?

We want this for cellphones, too -- touchscreen should be disabled
while the device is locked in the pocket -- but we really want the
touchscreen hardware to be powered down in that case (because it keeps
SoC busy and eats a _lot_ of electricity).

But simplistic "receive an event and then drop it if device is
inhibited" does not allow that...

Best regards,
Pavel

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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