Dell XPS 15 9560 - No brightness control

[manuell]

Hello,

I have the problem that I cannot control the screen brightness on my XPS 15 9560 notebook.

/sys/class/backlight is empty. I'm running latest Dell BIOS firmware 1.9.4. I tried all kinds of kernel parameters, such as acpi_osi and acpi_backlight, but without any effect. I'm running with Intel graphics card in UEFI mode.

kern.log attached.

root@eris:/etc/default# uname -a
Linux eris 4.15.0-20-generic #21-Ubuntu SMP Tue Apr 24 06:16:15 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Did this issue start happening after an update/upgrade? Was there a prior kernel version where you were not having this particular problem?

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.16 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.17-rc3

[Launchpad Janitor (janitor)]

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