(18.04 only) dell keyboard backlight timeout is wrong / ignoring default 10s to be 0s

[kevin flynn]

I'm using a dell E7440 laptop with a backlit keyboard, and the keyboard backlight fades out apparently the millisecond you hit a key, where it should behave like you hit a key and it stays lit for some time.

This worked in 16.04 on this laptop as of a few days ago, and now that I've installed 18.04, it seems to no longer function.

it is in fact set to 10s by default in /sys/devices/platform/dell-laptop/leds/dell\:\:kbd_backlight/stop_timeout

however that is apparently being ignored -- if you change that file then it starts working. That's sort of a workaround resolution, but it should work by default.

not a hugely important bug, but might save someone time and annoyance in the future, so im reporting it.

[kevin flynn (flynn-lives)]

solution: modify /sys/devices/platform/dell-laptop/leds/dell\:\:kbd_backlight/stop_timeout

changing the value to anything other than the default will cause it to start working

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1756815/+editstatus and add the package name in the text box next to the word Package.

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[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[alienflorina (alienflorina)]

modifying the stop_timeout file fixes it but after the next software update its set back to 60secs