Brightness hotkey broken on UX302LG

[tehownt]

Brightness control key is broken on UX302LG laptop.

Other hotkeys work (as per Bug #1270661) .

Soft control works and is able to dim screen brightness.

- Key does not output anything using xev.
- Nothing shows up using acpi_listen when pressing the key.

Tried acpi_type=vendor with no luck.

From discussions I had, next step would probably be to dump DSDT from /proc and try to recompile them with the Intel ASL compiler that could indicate where problem lies, fix the error and use that specific blob at boot time.

[tehownt (tehownt)]

See dmesg/kern.log output from Bug #1270661 or Bug #1265544.

[tehownt (tehownt)]

WORKAROUND:
Using
acpi_osi=
at boot parameter with NO value set, fixes the key and screen brightness is able to be controlled correctly by it.

[Launchpad Janitor (janitor)]

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

[Alberto Aguirre (albaguirre)]

I see the same behavior in a UX302LA laptop.

Using the workaround above fixes the issue.

[Launchpad Janitor (janitor)]

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

[penalvch (penalvch)]

tehownt, thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command, as it will automatically gather debugging information, in a terminal:
apport-collect 1270663

[tigre (tigreofearth)]

I can confirm that it doesn't work. Keyboard backlight shortcuts work, screen blacklight shortcut doesn't

[penalvch (penalvch)]

tigre, thank you for your comment. So your hardware and problem may be tracked, could you please file a new report with Ubuntu by executing the following in a terminal while booted into the default Ubuntu kernel (not a mainline one) via:
ubuntu-bug linux

For more on this, please read the official Ubuntu documentation:
Ubuntu Bug Control and Ubuntu Bug Squad: https://wiki.ubuntu.com/Bugs/BestPractices#X.2BAC8-Reporting.Focus_on_One_Issue
Ubuntu Kernel Team: https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies#Filing_Kernel_Bug_reports
https://wiki.ubuntu.com/Kernel/Policies/DuplicateBugs
Ubuntu Community: https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette

When opening up the new report, please feel free to subscribe me to it.

As well, please do not announce in this report you created a new bug report.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]