# Screen Blanking on/off

## cowboy0629

Sorry all hope I have this in the right place. Im having a issue with my laptop where when the screen blanks after so long of inactivity it seems that the backlight is turning on and off every 10 seconds +/- ... I never had (or noticed this before) more noticeable in the dark but also in daylight if sun is not shining on screen..  the backlight seems to be turning on and off every few seconds i have read allot on sccreen flicker but this is only happening when the system blanks the screen in console mode or x ...  

My system info

```

Linux acer 4.9.6-gentoo-r1 #2 SMP Mon Feb 13 12:28:24 EST 2017 x86_64 Intel(R) Pentium(R) CPU N3700 @ 1.60GHz GenuineIntel GNU/Linux

ACER Aspire ES 15  (ES1-531-P9QU)

Intel Pentium Quad Core Processor N3700 (up to 2.4 Ghz)

Intel HD Graphics 8 gig RAM

```

RED dmesg errors

```

[    0.261608] ACPI Error: No handler for Region [RAM_] (ffff8802774b49d8) [EmbeddedControl] (20160831/evregion-166)

[    0.262010] ACPI Error: Region EmbeddedControl (ID=3) has no handler (20160831/exfldio-299)

[    0.262408] ACPI Error: Method parse/execution failed [\_SB.PCI0.LPCB.EC0._REG] (Node ffff8802774b53e8), AE_NOT_EXIST (20160831/psparse-543)

[    0.263040] ACPI Error: No handler for Region [RAM_] (ffff8802774b49d8) [EmbeddedControl] (20160831/evregion-166)

[    0.263441] ACPI Error: Region EmbeddedControl (ID=3) has no handler (20160831/exfldio-299)

[    0.263833] ACPI Error: Method parse/execution failed [\_SB.PCI0.LPCB.EC0._REG] (Node ffff8802774b53e8), AE_NOT_EXIST (20160831/psparse-543)

[    5.042025] EXT4-fs (sda4): couldn't mount as ext3 due to feature incompatibilities

```

WHITE dmesg errors

```

[    0.025678] ENERGY_PERF_BIAS: Set to 'normal', was 'performance'

[    0.025868] ENERGY_PERF_BIAS: View and update with x86_energy_perf_policy(8)

[    1.198521] usb: port power management may be unreliable

[    4.574349] r8169 0000:01:00.0: can't disable ASPM; OS doesn't have ASPM control

[    8.302562] uvcvideo 1-3:1.0: Entity type for entity Extension 4 was not initialized!

[    8.302567] uvcvideo 1-3:1.0: Entity type for entity Extension 7 was not initialized!

[    8.302570] uvcvideo 1-3:1.0: Entity type for entity Processing 2 was not initialized!

[    8.302572] uvcvideo 1-3:1.0: Entity type for entity Camera 1 was not initialized!

[    8.353913] acer_wmi: Enabling Launch Manager failed: 0xe4 - 0x0

```

even though this is unrelated to the question if anyone knows how to get any of these errors out of the dmesg please chime in I know people say don't worry but the red really bugs me and I never had these errors last time I had gentoo on this system...  I tried Arch.. for a while and found I really liked Gentoo Community way better .. People here are willing to help where the arch people basically tell you are on your own..

Thanks in advance

 Mike Dennison

----------

## Roman_Gruber

is there a hardware light sensor for the screen?

Your "bios" is updated?

disable "Active-State Power Management" in your kernel, please. E.g. by passing pcie_aspm=off to the kernel

Are those hotkeys working?

http://www.spinics.net/lists/linux-input/msg12809.html

Looks like another "UEFI" related workaround ...

----------

## The Doctor

The Xorg screen blanking can be disabled with an xorg config file. The console is handled separately. I believe Roman_Gruber posted the solution for console only. Unless I am mistaken his solution will not affect X.

The xorg file should be /etc/X11/xorg.conf.d/40-monitor.conf and should contain 

```
section "ServerFlags" 

Option "blank time" "0" 

Option "standby time" "0" 

Option "suspend time" "0" 

Option "off time" "0" 

Option "dpms" "false" 

EndSection
```

This will stop the screen and backlight from being turned off in an xorg session.

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## cowboy0629

 *Roman_Gruber wrote:*   

> is there a hardware light sensor for the screen?
> 
> Your "bios" is updated?
> 
> disable "Active-State Power Management" in your kernel, please. E.g. by passing pcie_aspm=off to the kernel
> ...

 

Hi sorry been working far from home so not much time to play with my computers...

I not using UEFI  im using the legacy bios settings

BIOS is updated to most recent

Some of the Hotkeys work and Some don't

Oh and if I turn the touch pad off with the hot key I can't turn it back on until I reboot go into BIOS change the touchpad to advanced save exit gointo BIOS and change it back to basic.. for some reason gentoo won't see it at all in advanced mode

How do I pass  pcie_aspm=off this to the kernel 

thanks

 Mike

----------

## beizhuchun

you can try to set kernel config as :

CONFIG_X86_SYSFB=n

----------

## The Doctor

You can look that up by checking how to pass boot parameters using your bootloader of choice.

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## Roman_Gruber

 *Quote:*   

> Some of the Hotkeys work and Some don't 

 

you should check those kernel hidden settings for ACPI / notebooks. even those special hidden sections

also check for hints what dmesg says. if it may works with a livecd

It is for sure related

Assuming no hardware defect!

----------

## The Main Man

You need to run this command :

```
xset -dpms s off
```

Preferably have it auto-execute each time you login, various ways to do that so you choose  :Smile: 

----------

