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From:   Jingoo Han <jingoohan1@gmail.com>
To:     Pavel Machek <pavel@denx.de>,
        Daniel Thompson <daniel.thompson@linaro.org>,
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        Lee Jones <lee.jones@linaro.org>,
        Alexander Schremmer <alex@alexanderweb.de>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Han Jingoo <jingoohan1@gmail.com>
Subject: Re: New sysfs interface for privacy screens
Thread-Topic: New sysfs interface for privacy screens
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Date:   Sun, 6 Oct 2019 16:48:31 +0000
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> On 10/6/19, 7:04 AM, Pavel Machek wrote:
>
> Hi!
>
> > > >> I have been looking into adding Linux support for electronic priva=
cy
> > > >> 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 ide=
a 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.gi=
t/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?

I agree with your opinion. I also think that better solution can be conside=
red,
although there is already something in 5.4.

Best regards,
Jingoo Han

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