Comment 2 for bug 1028151

I can confirm this is present starting in 3.2.0-27.43. I've reverted back to 3.2.0-26.41 as a workaround.

The following line is present in dmesg with the newer kernel, but not when booting the older:
"samsung_laptop: enabled workaround for brightness stepping quirk"

I don't have access to an environment to further research root cause, unfortunately.

For anyone seeking a kludge to restore max brightness, only if downgrading the kernel isn't practical, you can do something like the following. Be aware that any brightness-changing events (Fn keys, screen dimming) will likely require doing this again.

[If you're on a different graphics chipset/driver, you'll have to substitute "intel_backlight" with the proper value. `ls /sys/class/backlight/` to see what's on your system. If you find more than one dir in there, try each until one has the desired effect.]

cat /sys/class/backlight/intel_backlight/max_brightness | sudo tee /sys/class/backlight/intel_backlight/brightness