Bug 1007999

Description of problem:

Since 3.10.x kernels, brightess is always on maximum level (even on the newest 3.10.11-200 kernel). Changing level to max or low by Fn keys os xbacklight do nothing, brightness is always on maximum. Bug was not on 3.9.x kernels, where brightness control worked. Affect Fedora 18 too.

Laptop is Lenovo B570e. From Fedora 16 (it was the first Fedora on this laptop) to 18 since 3.10.x, controlling brightness levels always worked.

Bug affects other laptops too. There is a topic about this on FedoraForums: http://forum.fedoraforum.org/showthread.php?p=1665803

- The only solution I've found is adding this line to /etc/default/grub:

GRUB_CMDLINE_LINUX_DEFAULT="acpi_osi=Linux acpi_backlight=vendor thinkpad-acpi.brightness_enable=0"
 
- Then execute as root:  grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg

- Then after restart Fn keys not work anymore, but brightness can be changed by xbacklight.

Lspci:

$ lspci
00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09)
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
00:16.0 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 (rev 04)
00:1a.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 (rev 05)
00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 05)
00:1c.0 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 (rev b5)
00:1c.1 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 2 (rev b5)
00:1c.3 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 4 (rev b5)
00:1d.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 (rev 05)
00:1f.0 ISA bridge: Intel Corporation HM65 Express Chipset Family LPC Controller (rev 05)
00:1f.2 IDE interface: Intel Corporation 6 Series/C200 Series Chipset Family 4 port SATA IDE Controller (rev 05)
00:1f.3 SMBus: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller (rev 05)
00:1f.5 IDE interface: Intel Corporation 6 Series/C200 Series Chipset Family 2 port SATA IDE Controller (rev 05)
02:00.0 Network controller: Qualcomm Atheros AR9285 Wireless Network Adapter (PCI-Express) (rev 01)
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 06)



Version-Release number of selected component (if applicable):

Kernels 3.10.x to newest 3.10.11-200



Steps to Reproduce:
1. Install Fedora 18/19 on HP or Lenovo laptops
2. Yum upgrade
3. Reboot system, brightness from start will be set to maximum and there is no way to change it.

Actual results:

- Brightess is always on maximum


Expected results:

- Fixed bug, so brightes can be controlled again by Fn keys and xbacklight like on 3.9.x kernels and olders kernels or Fedora versions


Additional info:

FedoraForums thread about this: http://forum.fedoraforum.org/showthread.php?p=1665803

Affects HP laptops too (see forum link above).