So I've had an openSUSE 13.2 (kernel 3.16.7-29) installation running on an Acer Aspire S7-392 for well over a year and have no problems until Sunday. I can't recall if I did an update or what, but I suddenly lost the ability to change the brightness on my laptop. BTW, I am using KDE4.

So far I've tried xbacklight and adding parameters to "GRUB_CMD_LINE" (acpi_backlight=vendor, acpi_osi=Linux) in /etc/default/grub, but nothing has worked thus far. I found that /sys/class/backlight is empty - which from what I've read, indicates that my computer thinks it's attached to a CRT monitor, and can imply a lack of driver support which I know to be false considering my fruitful year with this machine.

Oddly enough, as I booted it up today, many of my KDE desktop customizations were gone: custom icon for application launcher, desktop folders rearranged and placed in one of those window things, background reset, etc. Not sure if this things together can indicate a larger problem but I thought it may be relevant somehow.

What are some additional steps I can take to fix this?

  • Check you system logs (sudo journalctl) for any updates that happened. Could be the firmware you've been using has been uninstalled or blacklisted (the backlight problem). Desktop icons: Not sure how KDE4 stores these but maybe your home folder got corrupted. Compare your ~/.config file tree with a recent backup maybe?
    – kba
    Feb 16, 2016 at 23:23

1 Answer 1


Not a 'standard' fix but I upgraded to Tumbleweed (thus kernel upgrade too) and this fixed my issue. At least I know it was a kernel upgrade that broke it.

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