Re: [PATCH 0/4] TTY: fix Caps Lock LED

From: Samuel Thibault
Date: Fri Jan 27 2017 - 12:28:24 EST


Benjamin Tissoires, on Fri 27 Jan 2017 18:13:14 +0100, wrote:
> Well, it's quite an old issue, but it looks like no one cared much before :)

I did, actually.

> So by default, on Fedora and RHEL at least*, the Caps Lock LED is broken while
> in a VT.

Yes, and in Debian too, see
That was the trigger for my kbd LED work.

> I tracked down the issue to be a change in ckbcomp introduced because
> the kernel just can't properly handle all keymaps. However, if the keymap now
> works thanks to the work around in place, the LED just doesn't.

Yes, and ckbcomp now just has to properly set the LED trigger for
capslock. Something like:

echo kbd-ctrlllock > /sys/class/leds/input0::capslock/trigger


> This series aims at trying to have a consistent LEDs status while in VT.
> It detects the ckbcomp workaround (which seems mainline now),


> and syncs both caps lock with left control lock when it has to.


> This way, we shouldn't
> break existing user-space if the distribution changes the trigger to
> kbd-controllllock instead of kbd-capslock.


It's ckbcomp's fault for using another trigger. It's up to ckbcomp to
make sure that keyboard use the right trigger for the capslock led. The
kernel shouldn't try to circumvent that.