Brightness problem

**Evgenyi** · May 2nd, 2014

Hello, I have the same problem as a guy had - http://ubuntuforums.org/showthread.php?t=2088190
But I haven't got any folders in /sys/class/backlight.
It disappeared after I made manipulation with that instruction:
1. Open a terminal (Program - Accessories - Terminal)
2. Type in "sudo gedit /etc/default/grub" (without the "")
3. Find the line that says: GRUB_CMDLINE_LINUX="quiet splash"
4. Edit it so it says: GRUB_CMDLINE_LINUX="quiet splash acpi_backlight=vendor"
5. Save and exit
6. Run the command "sudo update-grub" (again without quotes of course)
7. Reboot and enjoy!

here is information that were asked:

BOOT_IMAGE=/boot/vmlinuz-3.13.0-24-generic root=UUID=6af82d53-e87d-480c-b345-b346a96c109e ro quiet splash acpi_backlight=vendor
1
/sys/class/backlight/*
cat: /sys/class/backlight/*/brightness: No such file or directory
cat: /sys/class/backlight/*/max_brightness: No such file or directory

Sony Corporation
VPCEH1L1R

01:00.0 VGA compatible controller [0300]: NVIDIA Corporation GF119M [GeForce 410M] [10de:1055] (rev a1) (prog-if 00 [VGA controller])
Subsystem: Sony Corporation Device [104d:908b]
Flags: bus master, fast devsel, latency 0, IRQ 16
Memory at d2000000 (32-bit, non-prefetchable) [size=16M]
Memory at c0000000 (64-bit, prefetchable) [size=256M]
Memory at d0000000 (64-bit, prefetchable) [size=32M]
I/O ports at 4000 [size=128]
[virtual] Expansion ROM at d3080000 [disabled] [size=512K]
Capabilities: [60] Power Management version 3
Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+
Capabilities: [78] Express Endpoint, MSI 00
Capabilities: [b4] Vendor Specific Information: Len=14 <?>
Capabilities: [100] Virtual Channel

video/brightnessup BRTUP 00000086 00000000 K
sony/hotkey SNY5001:00 00000001 00000011
sony/hotkey SNY5001:00 00000001 0000003b
video/brightnessdown BRTDN 00000087 00000000 K
sony/hotkey SNY5001:00 00000001 00000010
sony/hotkey SNY5001:00 00000001 0000003b

Please help me, my eyes promise

**raja.genupula** · May 2nd, 2014

http://askubuntu.com/questions/14905.../149265#149265

**Toz** · May 2nd, 2014

Evgenyi,

Can you remove the acpi_backlight=vendor kernel parameter, re-run "sudo update-grub" and reboot your computer (to get it back to the state it was before).

Then, can you run the following commands in a terminal window and post back the results:
1. Your current kernel boot line:

Code:

cat /proc/cmdline

2. Information about your video card(s):

Code:

lspci -k | grep -iA2 VGA

3. Information about your known backlight interfaces:

Code:

for interface in /sys/class/backlight/*; do echo -e "\n $interface"; cat $interface/{brightness,max_brightness,actual_brightness}; done

4. A listing of your loaded kernel modules:

Code:

lsmod

5. Your /var/log/Xorg.0.log file:

Code:

pastebinit /var/log/Xorg.0.log

...and post back the link that is generated.

**Evgenyi** · May 2nd, 2014

Code:

BOOT_IMAGE=/boot/vmlinuz-3.13.0-24-generic root=UUID=6af82d53-e87d-480c-b345-b346a96c109e ro quiet splash quiet splash

Code:

01:00.0 VGA compatible controller: NVIDIA Corporation GF119M [GeForce 410M] (rev a1)
	Subsystem: Sony Corporation Device 908b
	Kernel driver in use: nvidia

Code:

 /sys/class/backlight/acpi_video0
15
15
15

Code:

Module                  Size  Used by
ctr                    13049  2 
ccm                    17773  2 
pci_stub               12622  1 
vboxpci                23194  0 
vboxnetadp             25670  0 
vboxnetflt             27613  0 
vboxdrv               339502  3 vboxnetadp,vboxnetflt,vboxpci
cuse                   13445  3 
rfcomm                 69160  8 
bnep                   19624  2 
binfmt_misc            17468  1 
joydev                 17381  0 
snd_hda_codec_hdmi     46207  1 
uvcvideo               80885  0 
videobuf2_vmalloc      13216  1 uvcvideo
videobuf2_memops       13362  1 videobuf2_vmalloc
videobuf2_core         40664  1 uvcvideo
videodev              134688  2 uvcvideo,videobuf2_core
intel_rapl             18773  0 
x86_pkg_temp_thermal    14205  0 
intel_powerclamp       14705  0 
coretemp               13435  0 
kvm                   451511  0 
crct10dif_pclmul       14289  0 
crc32_pclmul           13113  0 
arc4                   12608  2 
ghash_clmulni_intel    13259  0 
snd_hda_codec_conexant    57441  1 
cryptd                 20359  1 ghash_clmulni_intel
btusb                  32412  0 
psmouse               102222  0 
bluetooth             395423  22 bnep,btusb,rfcomm
serio_raw              13462  0 
ath9k                 164164  0 
ath9k_common           13551  1 ath9k
ath9k_hw              453856  2 ath9k_common,ath9k
ath                    28698  3 ath9k_common,ath9k,ath9k_hw
mac80211              626489  1 ath9k
rtsx_pci_ms            18151  0 
memstick               16966  1 rtsx_pci_ms
snd_seq_midi           13324  0 
lpc_ich                21080  0 
snd_seq_midi_event     14899  1 snd_seq_midi
cfg80211              484040  3 ath,ath9k,mac80211
snd_rawmidi            30144  1 snd_seq_midi
snd_hda_intel          52355  5 
snd_hda_codec         192906  3 snd_hda_codec_hdmi,snd_hda_codec_conexant,snd_hda_intel
snd_hwdep              13602  1 snd_hda_codec
snd_pcm               102099  3 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel
snd_seq                61560  2 snd_seq_midi_event,snd_seq_midi
nvidia              10675249  52 
sony_laptop            54219  0 
snd_seq_device         14497  3 snd_seq,snd_rawmidi,snd_seq_midi
snd_page_alloc         18710  2 snd_pcm,snd_hda_intel
drm                   302817  2 nvidia
video                  19476  0 
snd_timer              29482  2 snd_pcm,snd_seq
snd                    69238  21 snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_hda_codec_conexant,snd_pcm,snd_seq,snd_rawmidi,snd_hda_codec,snd_hda_intel,snd_seq_device,snd_seq_midi
mei_me                 18627  0 
mac_hid                13205  0 
mei                    82274  1 mei_me
soundcore              12680  1 snd
parport_pc             32701  0 
ppdev                  17671  0 
lp                     17759  0 
parport                42348  3 lp,ppdev,parport_pc
hid_logitech_dj        18581  0 
usbhid                 52616  0 
hid                   106148  3 usbhid,hid_logitech_dj
rtsx_pci_sdmmc         23274  0 
r8169                  67581  0 
mii                    13934  1 r8169
ahci                   25819  2 
rtsx_pci               45956  2 rtsx_pci_ms,rtsx_pci_sdmmc
libahci                32168  1 ahci

http://paste.ubuntu.com/7382405/

**Evgenyi** · May 3rd, 2014

It doesn't work

**Toz** · May 3rd, 2014

Lets try this first:

If the /etc/X11/xorg.conf file exists, add:

Code:

Option "EnableBrightnessControl=1"

...to the "Device" section of that file.

If the file does not exist, then with root privileges, create the file /usr/share/X11/xorg.conf.d/20nvidia.conf with the following content:

Code:

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce 410M"
    Option         "RegistryDwords" "EnableBrightnessControl=1"
EndSection

Log out and back in again to test. If something goes wrong, simply delete that file and reboot to recover the system.