Arch Linux

ahura

Member

Registered: 2016-02-20

Posts: 57

[solved] How to disable power saving features using kernel parameters?

After a recent update, my laptop's monitor started flickering wildly, seemingly at random times.

Many users seem to have had this problem, and fixed it by disabling the Panel Self Refresh power saving feature. According to the wiki , this can by fixed by using the kernel parameter i915.enable_psr=0.

Following the wiki on kernel parameters, I append i915.enable_psr=0 to /etc/default/grub and regenerate grub.cfg, but get i915.enable_psr=0: command not found.

Am I missing something on how to change this, or is the error indicative of something else?

Last edited by ahura (2018-04-24 00:47:45)

loqs

Member

Registered: 2014-03-06

Posts: 17,372

Re: [solved] How to disable power saving features using kernel parameters?

Please post the contents of /etc/default/grub and the command you used to regenerate grub.cfg and its full output.

ahura

Member

Registered: 2016-02-20

Posts: 57

Re: [solved] How to disable power saving features using kernel parameters?

Command to regenerate grub: sudo grub-mkconfig -o /boot/grub/grub.cfg

Output: /etc/default/grub: line 50: i915.enable_psr=0: command not found

Full contents:

GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="Arch"
GRUB_CMDLINE_LINUX_DEFAULT=#"quiet"
GRUB_CMDLINE_LINUX=""

# Preload both GPT and MBR modules so that they are not missed
GRUB_PRELOAD_MODULES="part_gpt part_msdos"

# Uncomment to enable Hidden Menu, and optionally hide the timeout count
#GRUB_HIDDEN_TIMEOUT=5
#GRUB_HIDDEN_TIMEOUT_QUIET=true

# Uncomment to use basic console
GRUB_TERMINAL_INPUT=console

# Uncomment to disable graphical terminal
#GRUB_TERMINAL_OUTPUT=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
GRUB_GFXMODE=auto

# Uncomment to allow the kernel use the same resolution used by grub
GRUB_GFXPAYLOAD_LINUX=keep

# Uncomment if you want GRUB to pass to the Linux kernel the old parameter 
# format "root=/dev/xxx" instead of "root=/dev/disk/by-uuid/xxx" 
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
GRUB_DISABLE_RECOVERY=true

# Uncomment and set to the desired menu colors.  Used by normal and wallpaper 
# modes only.  Entries specified as foreground/background.
#GRUB_COLOR_NORMAL="light-blue/black"
#GRUB_COLOR_HIGHLIGHT="light-cyan/blue"

# Uncomment one of them for the gfx desired, a image background or a gfxtheme
#GRUB_BACKGROUND="/path/to/wallpaper"
#GRUB_THEME="/path/to/gfxtheme"

# Uncomment to get a beep at GRUB start
#GRUB_INIT_TUNE="480 440 1"

#GRUB_SAVEDEFAULT="true"

# Disable power save thingy to stop filckering
i915.enable_psr=0
i915.enable_rc6=0

loqs

Member

Registered: 2014-03-06

Posts: 17,372

Re: [solved] How to disable power saving features using kernel parameters?

Kernel_parameters#GRUB

To make the change persistent after reboot, while you could manually edit /boot/grub/grub.cfg with the exact line from above, the best practice is to:
    Edit /etc/default/grub and append your kernel options to the GRUB_CMDLINE_LINUX_DEFAULT line

You added two new lines to the end of the file instead of appending the options to the GRUB_CMDLINE_LINUX_DEFAULT string also should not have a # after the equals

ahura

Member

Registered: 2016-02-20

Posts: 57

Re: [solved] How to disable power saving features using kernel parameters?

Ah, thanks. Changing the default string line to

GRUB_CMDLINE_LINUX_DEFAULT="i915.enable_psr=0"

fixed it.

Last edited by ahura (2018-04-24 00:47:15)