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?