linux-kernel - Re: Spurious touchpad events with closed LID

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Date:   Thu, 29 Jun 2017 12:15:00 +0200
From:   Pavel Machek <pavel@....cz>
To:     Pali Rohár <pali.rohar@...il.com>
Cc:     Bastien Nocera <hadess@...ess.net>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        linux-kernel@...r.kernel.org, linux-input@...r.kernel.org
Subject: Re: Spurious touchpad events with closed LID

On Thu 2017-06-29 12:11:12, Pali Rohár wrote:
> On Thursday 29 June 2017 12:08:37 Pavel Machek wrote:
> > Hi!
> > 
> > On Thu 2017-06-29 09:31:02, Pali Rohár wrote:
> > > On Thursday 29 June 2017 00:44:27 Bastien Nocera wrote:
> > > > On Wed, 2017-06-28 at 22:15 +0200, Pavel Machek wrote:
> > > > > 
> > > > <snip>
> > > > > While policy normally belongs to userspace, I'd argue this is
> > > > > workaround for a hardware bug, and in-kernel solution would be
> > > > > acceptable.
> > > > > 
> > > > > Anyway, disable attribute would be nice first step.
> > > > 
> > > > It's already fixed for those of us on recent distributions. The
> > > > "ID_INPUT_TOUCHPAD_INTEGRATION=internal" touchpads will be disabled
> > > > when the lid is closed, when libinput is used to process the events.
> > > 
> > > But this does not fix other usage of /dev/input/* and also does not fix
> > > pressing spurious keys in linux virtual tty (ctrl+alt+f1). So it is not
> > > a fix.
> > > 
> > > Also important question is: How you detect which input device is
> > > "internal", non-removable part of notebook and which one is external?
> > > 
> > > You can have external USB touchpad, and also you can have external PS/2
> > > keyboard connected to docking station (which was e.g. my situation).
> > > 
> > > Also there are PS/2 to active USB converters, to make whole situation
> > > complicated.
> > > 
> > > And moreover some internal notebook keyboards are connected via USB and
> > > some touchpads via i2c/smbus.
> > > 
> > > I think this detection is not easy or at least I have no idea how to do
> > > properly. Existence of PS/2 keyboard does not mean it is internal and
> > > existence of USB keyboard does not mean it is external.
> > > 
> > > Maybe ACPI/DSDT provides some information? (No idea, just asking)
> > 
> > I'm not sure it is complex. You simply add DMI blacklist of the bad
> > systems, with IDs of bad devices.
> 
> My original request is to disable internal keyboard, touchpad and
> trackpoint on notebook when it is docked and LID is closed.
> 
> It has nothing to do with DMI blacklist or so.

Well, you have a buggy notebook. On non-buggy ones, touchpad will not
generate events when closed.

That's where the DMI blacklist comes to mind.

(Of course, disable attribute would still be nice for other cases.)
									Pavel

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

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