Backlight not working correctly

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Super-Nathan
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Backlight not working correctly

Post by Super-Nathan » Fri May 03, 2013 5:21

hardware
I have a Toshiba portege running XFCE 13.04

problem
1) The backlight does not adjust to all levels. all he way dark or bright is unacheivable.
2) After resuming from sleep, the brightness is unchangeable. The Indicator shows adjustment, but nothing happens. Areboot is required to fix.

What I have tried
My backlight never wants to play nice. In Debian or Manjaro booting with the lines:

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acpi_backlight=vendor and acpi_osi=Linux

In these distros this solves the problem

what i do know
in /sys/class/backlight there are two options: Intel_backlight and Toshiba

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echo 0 > brightness 
echo `cat max_brightness`  > brightness 
does effect the backlight, even after sleep.

I don't even know if it is an option, but i tried booting:

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acpi_backlight=intel_backlight
but that does nothing.

what i want
I want my brightness keys to actually adjust my screen brightness. so I prolly need to find a way to specify that i use the intel backlight and not the toshiba backlight.
echo "something useful" > /dev/null

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Fitzcarraldo
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Re: Backlight not working correctly

Post by Fitzcarraldo » Fri May 03, 2013 11:04

See under Notes in the following Wiki page:

LinLap - The Linux Laptop Wiki - Toshiba Portege Z830\Z835

Maybe that will help? If not, it could be that you need to apply the kernel patch mentioned in the post by Gentoo user Canek on 2013/02/11 on the same page.

EDIT: Also, have you tried using fnfx?

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equo install fnfx
FnFX enables owners of Toshiba laptops to change the LCD brightness, control the internal fan and use the special keys on their keyboard (Fn-x combinations, hot-keys) under Linux. The internal functions will give the possibility to map the Fn-Keys to functions like volume up/down, mute, suspend to disk, suspend to ram and switch LCD/CRT/TV-out. These functions heavily depend on the system and/or kernel configuration. You will need at least a kernel (v2.4.x, v2.5.x, v2.6.x) with ACPI and Toshiba support. See documentation for details.

Super-Nathan
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Re: Backlight not working correctly

Post by Super-Nathan » Sat May 04, 2013 1:31

Fitzcarraldo wrote:See under Notes in the following Wiki page:

LinLap - The Linux Laptop Wiki - Toshiba Portege Z830\Z835

Maybe that will help? If not, it could be that you need to apply the kernel patch mentioned in the post by Gentoo user Canek on 2013/02/11 on the same page.

EDIT: Also, have you tried using fnfx?

Code: Select all

equo install fnfx
FnFX enables owners of Toshiba laptops to change the LCD brightness, control the internal fan and use the special keys on their keyboard (Fn-x combinations, hot-keys) under Linux. The internal functions will give the possibility to map the Fn-Keys to functions like volume up/down, mute, suspend to disk, suspend to ram and switch LCD/CRT/TV-out. These functions heavily depend on the system and/or kernel configuration. You will need at least a kernel (v2.4.x, v2.5.x, v2.6.x) with ACPI and Toshiba support. See documentation for details.
LOL, I am the Initial author of this linlap post: http://www.linlap.com/toshiba_portege_z930

SO with that linlap link, I would have to patch and build a kernel, right? I would prefere kernel 3.9 because that fixes a LAN issue i have in the 3.8 series. I am very familiar with building Debian Kernels, but am very new to SAbayon/Gentoo, what is the best process? Do I build a kernel package and install it like I do with Debian or do I just do a regular source build and install?
echo "something useful" > /dev/null

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Fitzcarraldo
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Re: Backlight not working correctly

Post by Fitzcarraldo » Sat May 04, 2013 3:05

Although I build the kernel quite often on my two machines running Gentoo, I haven't rebuilt a kernel on my machines running SL in probably a couple of years, but the SL Wiki article HOWTO: Upgrade kernel using genkernel is probably still valid. You'll need to add the sabayon-distro Portage overlay first:

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equo install git
emerge --sync
layman -S
layman -d sabayon-distro
layman -a sabayon-distro
and you can install genkernel via Entropy rather than Portage:

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equo install genkernel

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