[LM19 MATE] Backlight Setting Resets

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WISEGUYTR
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[LM19 MATE] Backlight Setting Resets

Post by WISEGUYTR » Mon Aug 20, 2018 9:14 am

Just installed clean LM19MATE.

The background lights keep on forgetting it's setting after each reboot and suspend/wakeup. I have to manually open the Power Manager and click on the percentage bar to make it "remember". As a quick workaround I added the LCD Brightness applet to the command bar, but the problem still exists.

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System:   Host: MATE Kernel: 4.15.0-32-generic x86_64 bits: 64
              Desktop: MATE 1.20.1  Distro: Linux Mint 19 Tara
Machine: Device: laptop System: Hewlett-Packard product: HP ProBook 4530s v: A0001D02 serial: N/A
              Mobo: Hewlett-Packard model: 167C v: KBC Version 22.26 serial: N/A
              BIOS: Hewlett-Packard v: 68SRR Ver. F.63 date: 04/06/2017
Battery   BAT0: charge: 38.7 Wh 100.0% condition: 38.7/38.7 Wh (100%)
CPU:       Dual core Intel Core i5-2450M (-MT-MCP-) cache: 3072 KB
              clock speeds: max: 3100 MHz 1: 810 MHz 2: 805 MHz 3: 817 MHz
              4: 852 MHz
Graphics:Card: Intel 2nd Generation Core Integrated Graphics Controller
              Display Server: x11 (X.Org 1.19.6 ) driver: intel
              Resolution: 1366x768@60.03hz
              OpenGL: renderer: Mesa DRI Intel Sandybridge Mobile
              version: 3.3 Mesa 18.0.5

gm10
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Re: [LM19 MATE] Backlight Setting Resets

Post by gm10 » Mon Aug 20, 2018 9:23 am

Run this (it likely won't produce any output):

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sudo chown -R $USER:$USER $HOME
Log out and back in or reboot to see if that fixed it.

WISEGUYTR
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Re: [LM19 MATE] Backlight Setting Resets

Post by WISEGUYTR » Thu Aug 23, 2018 8:54 am

gm10 wrote:
Mon Aug 20, 2018 9:23 am
Run this (it likely won't produce any output):

Code: Select all

sudo chown -R $USER:$USER $HOME
Log out and back in or reboot to see if that fixed it.
Tried it, but when it wakes up from suspend, it's the same. The brightness sets to max.

gm10
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Re: [LM19 MATE] Backlight Setting Resets

Post by gm10 » Thu Aug 23, 2018 9:22 am

Hmm, no idea why it wouldn't save then. You could script it to be set automatically I guess.

Set your brightness to what you want it to be. Then run this

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P=/sys/class/backlight/*/brightness;find $P;cat $P
It should output exactly one path and one number. If it outputs anything else then post the output and don't continue with the next step.

Otherwise run this:

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P=/sys/class/backlight/*/brightness;T=/etc/rc.local;printf "echo $(cat $P) > $(find $P)\n"|sudo tee $T;sudo chmod +x $T
Reboot and see if it works on boot. If it does we'll also script it upon resume.

WISEGUYTR
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Re: [LM19 MATE] Backlight Setting Resets

Post by WISEGUYTR » Tue Sep 04, 2018 5:35 pm

It actually saves it, but for some reason it forgets to check it after suspend. I mean when I look at the Power Settings, I see that it is in the set position after wake up from suspend. When I click on the bar to tune the brightness, it suddenly "remembers it".

I am wondering if there's some other place to set the brightness than this one.

WISEGUYTR
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Re: [LM19 MATE] Backlight Setting Resets

Post by WISEGUYTR » Sun Sep 23, 2018 7:01 am

gm10 wrote:
Thu Aug 23, 2018 9:22 am
Hmm, no idea why it wouldn't save then. You could script it to be set automatically I guess.

Set your brightness to what you want it to be. Then run this

Code: Select all

P=/sys/class/backlight/*/brightness;find $P;cat $P
It should output exactly one path and one number. If it outputs anything else then post the output and don't continue with the next step.

Otherwise run this:

Code: Select all

P=/sys/class/backlight/*/brightness;T=/etc/rc.local;printf "echo $(cat $P) > $(find $P)\n"|sudo tee $T;sudo chmod +x $T
Reboot and see if it works on boot. If it does we'll also script it upon resume.
The results I get are :

/sys/class/backlight/acpi_video0/brightness
/sys/class/backlight/intel_backlight/brightness
20
168

gm10
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Re: [LM19 MATE] Backlight Setting Resets

Post by gm10 » Sun Sep 23, 2018 7:17 am

Ah, one of those situations. Can you try the following, run this from a terminal:

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xed admin:///etc/default/grub
In the editor that pops up, authenticate then find the GRUB_CMDLINE_LINUX_DEFAULT line and add acpi_backlight=none so that it looks something like this

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GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=none"
(and potentially more parameters if you had already added your own)

Save the file, run

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sudo update-grub
and after a reboot your backlight might work correctly. It's also possible you'll lose backlight control completely though. Let me know.

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