Message-ID: <5447DF2D.7090109@gmail.com>
Date: Wed, 22 Oct 2014 19:45:33 +0300
From: Giedrius Statkevicius <giedriuswork@gmail.com>
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To: =?UTF-8?B?w4lyaWMgUGllbA==?= <eric.piel@tremplin-utc.net>,
        Darren Hart <dvhart@infradead.org>
CC: platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC] platform: hp_accel: add a i8042 filter to remove
 accelerometer data
References: <1413665962-3830-1-git-send-email-giedriuswork@gmail.com> <20141021214508.GF20951@vmdeb7> <5447AF1F.1060806@gmail.com> <5447BD06.70109@tremplin-utc.net>
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On 2014.10.22 17:19, Éric Piel wrote:
> On the HP laptop I had (with HPQ0004), no fake keys were reported.
I guess this is a new "feature", then.

> It should be noted that on my laptop, the accelerometer is completely
> decoupled from the hard disk. For example, when freefall is detected,
> nothing else happens (that's why you need to run a daemon that will
> listen to the event, and park the disk head). Looking at the bug report,
> it seems your laptop does a lot behind the OS, because apparently the
> disk head is parked automatically. So maybe the scancodes is a new

I'm sorry if I made the impression that it happens automatically but
actually I am running a daemon compiled from
Documentation/laptops/freefall.c. Nothing else is running on top of
linux to park the head when a free fall is detected.

> "feature" they have added in order to more easily report what's
> happening in the back.
> Now, more related to your proposed solution: is this really what we
> want? What's wrong with the current state excepted for some warning
> messages in dmesg? Do we really want to plain drop this information

Well, these are not just a few messages but a lot of them and they clog
the system log, makes it hard to notice the actual useful information,
wastes disk space, etc.

> provided by the hardware? How about just associating the scancodes to
> meaningful keycodes? (I guess one reason no to do that is that it'd
> likely require creating new keycodes corresponding to these pretty
> atypical events in the input layer).

The free fall detection is already handled by lis3lv02d and hp_accel on
hp laptops with this feature and information is provided through
/dev/freefall so, in my opinion, the way to go is to completely drop
these scancodes.

> 
> Is there maybe some general policy about what do to hardware that
> generate such special scancodes?

Really not sure. BTW, I wonder if the same stuff happens on HPQ6007.

Thanks,
Giedrius
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