intel_backlight with no value...

gor0 · 02-25-2015, 03:51 PM

howdy folks...

bad news: I'm gettin BLIND cause can't reduce brightness

got my /sys/class/backlight/intel_backlight(actual,brightness and max) empty I mean NO values on each

[Fn] + [down-up keys] doesn't work ... neither apci backlight vendor on kernel ...

how to fix it ?

tia!

ReaperX7 · 02-25-2015, 03:54 PM

Are you using a laptop?

gor0 · 02-25-2015, 03:59 PM

yep buddie !

Head_on_a_Stick · 02-25-2015, 04:03 PM

Which distribution (and version, if applicable) is this?

What is the output of:

Code:

lspci -knn|grep -iA3 vga

Have you tried the various kernel parameters:
https://wiki.archlinux.org/index.php...d-line_options

You can test these by simply pressing "e" at the GRUB menu (if you use that), adding the parameter at the end of the line that starts with "linux" and pressing <Ctrl>+x to boot.

gor0 · 02-25-2015, 04:08 PM

[QUOTE=Head_on_a_Stick;5323340]

What is the output of:

Code:

lspci -knn|grep -iA3 vga

Code:

# lspci -knn|grep -iA3 vga
00:02.0 VGA compatible controller [0300]: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0106] (rev 09)
	Subsystem: Acer Incorporated [ALI] Device [1025:0718]
	Kernel driver in use: i915
	Kernel modules: i915

GRUB is governed by Debian's partition! >>> sda3 | sda4 bleedin-edge | sda5 mint | sda6 slack

Head_on_a_Stick · 02-25-2015, 04:20 PM

Edit the file at /etc/default/grub and add the kernel parameter(s) inside the quotation marks on the GRUB_CMDLINE_LINUX line then run:

Code:

# update-grub

gor0 · 02-25-2015, 04:21 PM

Quote:

Originally Posted by Head_on_a_Stick

Code:

# update-grub

Code:

# update-grub
bash: update-grub: command not found

gor0 · 02-25-2015, 04:37 PM

unbareable to use Slack with full brightness!

Head_on_a_Stick · 02-25-2015, 04:41 PM

Quote:

Originally Posted by gor0

Code:

# update-grub
bash: update-grub: command not found

Hmmm...

Try:

Code:

# grub-mkconfig -o /boot/grub/grub.cfg

I'm not using a bootloader ATM so this is all from (rusty) memory...

gor0 · 02-25-2015, 04:52 PM

Quote:

Originally Posted by Head_on_a_Stick

Try:

Code:

# grub-mkconfig -o /boot/grub/grub.cfg

thx 4 reply buddie!

but...

bad news:

Code:

# grub-mkconfig -o /boot/grub/grub.cfg
/usr/sbin/grub-probe: error: cannot find a device for / (is /dev mounted?).

Head_on_a_Stick · 02-25-2015, 04:57 PM

Are you trying to do this from a live distribution?

What is the output of:

Code:

# lsblk -f

gor0 · 02-25-2015, 05:04 PM

again tia!

Code:

# lsblk -f
NAME   FSTYPE LABEL    UUID                                 MOUNTPOINT
sda                                                         
├─sda1 ext4            alphanumeric 
├─sda2 ext4   EFI Boot      "
├─sda3 ext4                 "
├─sda4 btrfs  root          "                               /run/media/root/root
├─sda5 ext4                 "   
└─sda6 btrfs           alphanumeric                        /
sr0

Head_on_a_Stick · 02-25-2015, 05:08 PM

I'll look into this further tomorrow -- I have to go to sleep now.

For now, just edit the individual GRUB menu entries as I described in post #4 and check if the various kernel parameters actually do anything.

gor0 · 02-25-2015, 05:14 PM

momentarily

this did the job:

http://www.linuxquestions.org/questi...4/#post5247239

Code:

echo 100 > /sys/class/backlight/intel_backlight/brightness

gor0 · 02-25-2015, 07:49 PM

How to update /etc/default/grub ?