Not able to control Brightness in my VAIO CW15FG laptop

[wizardvenkat]

Before installing nvidia drivers from software-properties-gtk, I had problem when ubuntu starts..
I get a plain purple screen after which I get the login screen.
While shut down I get the usual Ubuntu screen (the purple screen with Ubuntu written and an animation indicating that shutdown /restart process is going on)

After installing the nvidia drivers, I get a text "Ubuntu 12.10" with no loading animation. and sometimes I get it with a black background on it. And while shutting down, I just get my screen blanked. No acknowledgement about the Ubuntu getting shut down. I've to to look at the Power LED to make sure my PC is turned off...

Is that something to do with/related to the brightness issue ???

[wizardvenkat]

Did the screen brightness change?

No, no changes on the screen

[Toz]

Before installing nvidia drivers from software-properties-gtk, I had problem when ubuntu starts..
I get a plain purple screen after which I get the login screen.
While shut down I get the usual Ubuntu screen (the purple screen with Ubuntu written and an animation indicating that shutdown /restart process is going on)

After installing the nvidia drivers, I get a text "Ubuntu 12.10" with no loading animation. and sometimes I get it with a black background on it. And while shutting down, I just get my screen blanked. No acknowledgement about the Ubuntu getting shut down. I've to to look at the Power LED to make sure my PC is turned off...

Is that something to do with/related to the brightness issue ???

More likely its related to the install of the nvidia drivers. Unfortunately, I don't have an nvidia card and can't comment. You might want to create another thread afterwards to discuss that issue.

In the meantime, does that command change the screen brightness for you?

echo 4 | sudo tee /sys/class/backlight/sony/brightness

You can also try:

echo 1 | sudo tee /sys/class/backlight/sony/brightness

...to try to get more of an effect.

[wizardvenkat]

More likely its related to the install of the nvidia drivers. Unfortunately, I don't have an nvidia card and can't comment. You might want to create another thread afterwards to discuss that issue.

In the meantime, does that command change the screen brightness for you?

echo 4 | sudo tee /sys/class/backlight/sony/brightness

You can also try:

echo 1 | sudo tee /sys/class/backlight/sony/brightness

...to try to get more of an effect.

No changes on the screen...

[Toz]

That's interesting. Can you try re-installing nvidiabl (https://github.com/guillaumezin/nvidiabl/downloads) and then again try running:

for interface in /sys/class/backlight/*; do echo $interface; cat $interface/brightness; cat $interface/actual_brightness; cat $interface/max_brightness; done

Lets see if we can get a backlight interface that we can manipulate.

[wizardvenkat]

After I re-installed nvidiabl drivers again, I get

/sys/class/backlight/nvidia_backlight
34487
126
127
/sys/class/backlight/sony
1
1
7

after typing
for interface in /sys/class/backlight/*; do echo $interface; cat $interface/brightness; cat $interface/actual_brightness; cat $interface/max_brightness; done

[Toz]

Do either of these commands dim the screen brightness:

echo 64 | sudo tee /sys/class/backlight/nvidia_backlight/brightness

echo 4 | sudo tee /sys/class/backlight/sony/brightness

Also, what does the following return:

lsmod

[wizardvenkat]

Finally !!! I'm able to control the brightness through the code

echo 20 | sudo tee /sys/class/backlight/nvidia_backlight/brightness

However, the code

echo 1 | sudo tee /sys/class/backlight/sony/brightness

still doesnt work....

The results for lsmod is :

Module                  Size  Used by
usb_storage            48838  0 
uas                    17844  0 
rfcomm                 46619  0 
bnep                   18140  2 
parport_pc             32688  0 
bluetooth             209199  10 rfcomm,bnep
ppdev                  17073  0 
binfmt_misc            17500  1 
joydev                 17457  0 
snd_hda_codec_hdmi     32007  4 
arc4                   12529  2 
nvidia              11257759  42 
coretemp               13400  0 
snd_hda_codec_realtek    77876  1 
snd_hda_intel          33491  5 
snd_hda_codec         134212  3 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel
snd_hwdep              13602  1 snd_hda_codec
snd_pcm                96580  3 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec
snd_seq_midi           13324  0 
snd_rawmidi            30512  1 snd_seq_midi
snd_seq_midi_event     14899  1 snd_seq_midi
snd_seq                61521  2 snd_seq_midi,snd_seq_midi_event
mxm_wmi                12979  0 
nvidiabl               40764  0 
snd_timer              29425  2 snd_pcm,snd_seq
snd_seq_device         14497  3 snd_seq_midi,snd_rawmidi,snd_seq
snd                    78734  20 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_rawmidi,snd_seq,snd_timer,snd_seq_device
iwlwifi               386826  0 
mac80211              539908  1 iwlwifi
uvcvideo               76749  0 
videobuf2_core         32851  1 uvcvideo
videodev              120309  2 uvcvideo,videobuf2_core
soundcore              15047  1 snd
videobuf2_vmalloc      12860  1 uvcvideo
video                  19335  0 
videobuf2_memops       13368  1 videobuf2_vmalloc
psmouse                95552  0 
cfg80211              206566  2 iwlwifi,mac80211
snd_page_alloc         18484  2 snd_hda_intel,snd_pcm
lpc_ich                17061  0 
sony_laptop            54039  0 
wmi                    19070  1 mxm_wmi
mac_hid                13205  0 
serio_raw              13215  0 
microcode              22803  0 
lp                     17759  0 
parport                46345  3 parport_pc,ppdev,lp
firewire_ohci          40401  0 
sky2                   58111  0 
firewire_core          64368  1 firewire_ohci
crc_itu_t              12707  1 firewire_core
sdhci_pci              18616  0 
sdhci                  32645  1 sdhci_pci

So how do I control the brightness from the GUI (slider in 'Brightness & Lock' utility and hotkeys) ?

[Toz]

Ok, lets make the following changes and see what happens.

Create the following files with the following content (you will need root privileges to do this, so something like "gksu gedit <file>" where <file> is: )

1. /etc/acpi/events/sony-brightness-up

event=sony/hotkey SNC 00000001 00000011
action=/etc/acpi/brightup.sh

2. /etc/acpi/events/sony-brightness-down

event=sony/hotkey SNC 00000001 00000010
action=/etc/acpi/brightdown.sh

3. /etc/acpi/brightdown.sh

#!/bin/bash
curr=`cat /sys/class/backlight/nvidia_backlight/actual_brightness`
if [ $curr -gt 11 ]; then
   curr=$((curr-11));
   echo $curr  > /sys/class/backlight/nvidia_backlight/brightness;
fi

4. /etc/acpi/brightup.sh

#!/bin/bash
curr=`cat /sys/class/backlight/nvidia_backlight/actual_brightness`
if [ $curr -lt 117 ]; then
   curr=$((curr+11));
   echo $curr  > /sys/class/backlight/nvidia_backlight/brightness;
fi

Make all 4 of those scripts executable via:

sudo chmod +x /etc/acpi/events/sony-brightness-up
sudo chmod +x /etc/acpi/events/sony-brightness-down
sudo chmod +x /etc/acpi/brightdown.sh
sudo chmod +x /etc/acpi/brightup.sh

Restart acpid:

sudo service acpid restart

The function keys should now work.

Let me know if the gui controls work as well (you should probably log out and back in again to check the gui controls).



EDIT: To make the gui controls work, I believe you need to create (if it doesn't already exist) the file /etc/modprobe.d/nvidiabl with the following contents:

options nvidiabl type=firmware

...and reboot, or:

sudo modprobe -r nvidiabl
sudo modprobe nvidiabl type=firmware

[wizardvenkat]

Thanks a lot Toz !!
Everything works fine now...
The hot keys and the GUI control.
But still I don't know why my Brightness resets to maximum when I open Firefox or Thunderbird ?
It does not happen if I open other softwares..