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Date:   Sun, 6 Oct 2019 13:04:56 +0200
From:   Pavel Machek <pavel@denx.de>
To:     Daniel Thompson <daniel.thompson@linaro.org>, alex@alexanderweb.de,
        andriy.shevchenko@linux.intel.com
Cc:     Jani Nikula <jani.nikula@linux.intel.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Mat King <mathewk@google.com>, rafael@kernel.org,
        gregkh@linuxfoundation.org, Ross Zwisler <zwisler@google.com>,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        Jingoo Han <jingoohan1@gmail.com>,
        Rajat Jain <rajatja@google.com>,
        Lee Jones <lee.jones@linaro.org>,
        Alexander Schremmer <alex@alexanderweb.de>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: Re: New sysfs interface for privacy screens
Message-ID: <20191006110455.GC24605@amd>
References: <CAL_quvRknSSVvXN3q_Se0hrziw2oTNS3ENNoeHYhvciCRq9Yww@mail.gmail.com>
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Hi!

> > >> I have been looking into adding Linux support for electronic privacy
> > >> screens which is a feature on some new laptops which is built into t=
he
> > >> display and allows users to turn it on instead of needing to use a
> > >> physical privacy filter. In discussions with my colleagues the idea =
of
> > >> using either /sys/class/backlight or /sys/class/leds but this new
> > >> feature does not seem to quite fit into either of those classes.
> > >
> > > FWIW, it seems that you're not alone in this; 5.4 got some support for
> > > such screens if I understand things correctly:
> > >
> > >   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/=
commit/?id=3D110ea1d833ad
> >=20
> > Oh, I didn't realize it got merged already, I thought this was
> > related...
> >=20
> > So we've already replicated the backlight sysfs interface problem for
> > privacy screens. :(
>=20
> I guess... although the Thinkpad code hasn't added any standard
> interfaces (no other laptop should be placing controls for a privacy
> screen in /proc/acpi/ibm/... ). Maybe its not too late.

There's new interface for controlling privacyguard... but perhaps we
need better solution than what went in 5.4. Perhaps it should be
reconsidered?

Best regards,
									Pavel
--=20
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo=
g.html

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