Comment 8 for bug 1197482

using "acpi_backlight=vendor" on Saucy.

Before suspend & resume the behaviour of the led-backlight pressing F1 or F2 key is adjustable.
Checking the register `/sys/class/backlight/intel_backlight/brightness` the range from 0 to 2770 can be operated in 21 steps.
After resume still the full range is triggered with the F1 to F2 keys, but here the backlight is turned off completely for all values less than 2280 and fully turned on for all values greater 2290.

Setting the brightness with `echo 2289 > /sys/class/backlight/intel_backlight/brightness` the led backlight starts to flicker in a period of approx 1sec.

DistroRelease: Ubuntu 13.10
Package: linux-image-3.11.0-12-generic 3.11.0-12.19 [modified: boot/vmlinuz-3.11.0-12-generic]
ProcVersionSignature: Ubuntu 3.11.0-12.19-generic 3.11.3
Uname: Linux 3.11.0-12-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.12.5-0ubuntu2
Architecture: amd64
InstallationDate: Installed on 2013-10-17 (1 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
MachineType: Apple Inc. MacBookAir6,2
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.11.0-12-generic.efi.signed root=UUID=77b6a0d2-1d2f-480c-9e22-730bc9b73fed ro pcie_aspm=force i915.i915_enable_rc6=1 i915.i915_enable_fbc=1 i915.lvds_downclock=1 acpi_backlight=vendor
RelatedPackageVersions:
 linux-restricted-modules-3.11.0-12-generic N/A
 linux-backports-modules-3.11.0-12-generic N/A
 linux-firmware 1.116