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Date:   Wed, 2 Oct 2019 09:46:50 -0600
From:   Jonathan Corbet <corbet@lwn.net>
To:     Mat King <mathewk@google.com>
Cc:     linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        gregkh@linuxfoundation.org, rafael@kernel.org,
        Ross Zwisler <zwisler@google.com>,
        Rajat Jain <rajatja@google.com>,
        Lee Jones <lee.jones@linaro.org>,
        Daniel Thompson <daniel.thompson@linaro.org>,
        Jingoo Han <jingoohan1@gmail.com>,
        Alexander Schremmer <alex@alexanderweb.de>
Subject: Re: New sysfs interface for privacy screens
Message-ID: <20191002094650.3fc06a85@lwn.net>
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On Tue, 1 Oct 2019 10:09:46 -0600
Mat King <mathewk@google.com> wrote:

> I have been looking into adding Linux support for electronic privacy
> screens which is a feature on some new laptops which is built into the
> 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=110ea1d833ad

jon