New sysfs interface for privacy screens

[Daniel Thompson]

On Thu, Oct 03, 2019 at 11:19:13AM +0300, Jani Nikula wrote:
> On Wed, 02 Oct 2019, Jonathan Corbet <corbet at lwn.net> wrote:
> > On Tue, 1 Oct 2019 10:09:46 -0600
> > Mat King <mathewk at 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
> 
> Oh, I didn't realize it got merged already, I thought this was
> related...
> 
> So we've already replicated the backlight sysfs interface problem for
> privacy screens. :(

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.


Daniel.