Page 2 of 2 FirstFirst 12
Results 11 to 18 of 18

Thread: Samsung NP300V5A-S0CIN brightness issue.

  1. #11
    Join Date
    May 2009
    Location
    Bangalore, India
    Beans
    39
    Distro
    Ubuntu 13.04 Raring Ringtail

    Re: Samsung NP300V5A-S0CIN brightness issue.

    This is the o/p

    Code:
    dinesh@dinesh-lt:~$ grep . /sys/class/backlight/*/*
    /sys/class/backlight/acpi_video0/actual_brightness:7
    /sys/class/backlight/acpi_video0/bl_power:0
    /sys/class/backlight/acpi_video0/brightness:7
    grep: /sys/class/backlight/acpi_video0/device: Is a directory
    /sys/class/backlight/acpi_video0/max_brightness:7
    grep: /sys/class/backlight/acpi_video0/power: Is a directory
    grep: /sys/class/backlight/acpi_video0/subsystem: Is a directory
    /sys/class/backlight/acpi_video0/type:firmware
    /sys/class/backlight/acpi_video1/actual_brightness:7
    /sys/class/backlight/acpi_video1/bl_power:0
    /sys/class/backlight/acpi_video1/brightness:0
    grep: /sys/class/backlight/acpi_video1/device: Is a directory
    /sys/class/backlight/acpi_video1/max_brightness:7
    grep: /sys/class/backlight/acpi_video1/power: Is a directory
    grep: /sys/class/backlight/acpi_video1/subsystem: Is a directory
    /sys/class/backlight/acpi_video1/type:firmware
    /sys/class/backlight/intel_backlight/actual_brightness:309
    /sys/class/backlight/intel_backlight/bl_power:0
    /sys/class/backlight/intel_backlight/brightness:4648
    grep: /sys/class/backlight/intel_backlight/device: Is a directory
    /sys/class/backlight/intel_backlight/max_brightness:4648
    grep: /sys/class/backlight/intel_backlight/power: Is a directory
    grep: /sys/class/backlight/intel_backlight/subsystem: Is a directory
    /sys/class/backlight/intel_backlight/type:raw

  2. #12
    Join Date
    Jun 2005
    Location
    Toronto, Canada
    Beans
    Hidden!
    Distro
    Xubuntu 14.04 Trusty Tahr

    Re: Samsung NP300V5A-S0CIN brightness issue.

    Can you post back:
    Code:
    cat /proc/cmdline
    Which of the following sets of commands actually change the brightness:
    Code:
    echo 3 | sudo tee /sys/class/backlight/acpi_video0/brightness
    echo 7 | sudo tee /sys/class/backlight/acpi_video0/brightness
    Code:
    echo 5 | sudo tee /sys/class/backlight/acpi_video1/brightness
    echo 0 | sudo tee /sys/class/backlight/acpi_video1/brightness
    Code:
    echo 2324 | sudo tee /sys/class/backlight/intel_backlight/brightness
    echo 4648 | sudo tee /sys/class/backlight/intel_backlight/brightness

  3. #13
    Join Date
    May 2009
    Location
    Bangalore, India
    Beans
    39
    Distro
    Ubuntu 13.04 Raring Ringtail

    Re: Samsung NP300V5A-S0CIN brightness issue.

    O/p for cat /proc/cmdline is

    Code:
    BOOT_IMAGE=/boot/vmlinuz-3.9.0-030900-generic root=UUID=a526fb85-2653-479a-8aa5-035a2281db46 ro quiet splash
    Following lines change the brightness.


    echo 2324 | sudo tee /sys/class/backlight/intel_backlight/brightnessecho 4648 | sudo tee /sys/class/backlight/intel_backlight/brightness

    echo 3 | sudo tee /sys/class/backlight/acpi_video0/brightnessecho 7 | sudo tee /sys/class/backlight/acpi_video0/brightness

  4. #14
    Join Date
    Jun 2005
    Location
    Toronto, Canada
    Beans
    Hidden!
    Distro
    Xubuntu 14.04 Trusty Tahr

    Re: Samsung NP300V5A-S0CIN brightness issue.

    Quote Originally Posted by ttsdinesh View Post
    O/p for cat /proc/cmdline is

    Code:
    BOOT_IMAGE=/boot/vmlinuz-3.9.0-030900-generic root=UUID=a526fb85-2653-479a-8aa5-035a2281db46 ro quiet splash
    You are missing the acpi_iso=Linux acpi_backlight=vendor kernel parameters from post #2. Can you re-add them, this time follow the "Permanently Add a Kernel Boot Parameter" instructions in the "Kernel Boot Parameters" link in my signature. After you have rebooted, check that the parameters are in effect (should be displayed in the results of "cat /proc/cmdline").

    Then, check the brightness again, especially after a resume. If the problem persists, reply back with:
    Code:
    cat /proc/cmdline
    Code:
    for i in /sys/class/backlight/*; do echo $i; cat $i/brightness; cat $i/max_brightness; done
    ...and try once again to see which of the interfaces allow for brightness adjustements based on my previous post.

  5. #15
    Join Date
    May 2009
    Location
    Bangalore, India
    Beans
    39
    Distro
    Ubuntu 13.04 Raring Ringtail

    Re: Samsung NP300V5A-S0CIN brightness issue.

    This is the line in my /etc/default/grub

    Code:
    GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" acpi_osi=Linux acpi_backlight=vendor
    Is this correct or should it be

    Code:
    GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor"

    I'm confused in adding the parameter inside the double quote. Please provide me an example.

  6. #16
    Join Date
    Jun 2005
    Location
    Toronto, Canada
    Beans
    Hidden!
    Distro
    Xubuntu 14.04 Trusty Tahr

    Re: Samsung NP300V5A-S0CIN brightness issue.

    Quote Originally Posted by ttsdinesh View Post
    Code:
    GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor"
    ^^^^^This option is correct. Save the file then run:
    Code:
    sudo update-grub
    ...then reboot.

  7. #17
    Join Date
    May 2009
    Location
    Bangalore, India
    Beans
    39
    Distro
    Ubuntu 13.04 Raring Ringtail

    Thumbs up Re: Samsung NP300V5A-S0CIN brightness issue.

    Now when I reboot the brightness is not set to 100% but around 80%. But it is ok for me. When I suspend and open again the brightness is preserved.

    Thank you Toz !!

  8. #18
    Join Date
    Aug 2007
    Location
    From the land down under
    Beans
    1,245
    Distro
    Ubuntu Development Release

    Re: Samsung NP300V5A-S0CIN brightness issue.

    Closed at OP request.
    // Blog

Page 2 of 2 FirstFirst 12

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •