What is i915.modeset=1 for?

Question

I'm running Ubuntu 13.10 and since I upgraded to kernel 3.12.8 (build from source, including ubuntu patches) on a ivybridge video, the boot spash screen was flickering and messing up.

So I googled around and tried adding i915.modeset=1 paramenter to grub (without really knowing what I was doing) and magically the spash screen was fixed and I also noticed a much smoother scrolling of window contents (e.g a web page in chrome).

So I just would like to know more about i915.modeset=1.

score 7 · Accepted Answer · edited Apr 13 '17 at 12:22

7

You are using whats called Kernel Mode Setting (KMS) to make sure that your Intel graphic drivers are loaded early in the boot process, therefore making the "fancy" boot screen display correctly.

Kernel mode-setting (KMS) shifts responsibility for selecting and setting up the graphics mode from X.org to the kernel. When X.org is started, it then detects and uses the mode without any further mode changes. This promises to make booting faster, more graphical, and less flickery https://askubuntu.com/questions/1080/what-is-kernel-mode-setting

Also see https://wiki.archlinux.org/index.php/Kernel_Mode_Setting#Early_KMS_start

edited Apr 13 '17 at 12:22

Community

1

answered Jan 23 '14 at 12:48

M_dk

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13

Thanks for yuor answer. I know about KMS. I just want to now specifically about what the "i915.modeset=1" does with Intel driver, why it is required and why not i915.modeset=0 etc. – lviggiani Jan 23 '14 at 13:01
3

By setting i915.modeset=0 or nomodeset you would disble Kernel mode setting and instead let the X server handle the modesetting. – M_dk Jan 23 '14 at 13:26
Did you get the answer to your question or do you need anything else clarified? – M_dk Jan 28 '14 at 10:10

score 1 · Answer 2 · edited Dec 20 '18 at 09:58

My case is on Intel Atom D2500HN mobo where there is blank/black screen after grub

My solution:

~$ sudo <your_editor> /etc/default/grub
##video=LVDS-1:d  is disabling LVDS-1 port which some kernel version might be directing the video to that port on default despite your mobo might not have such a port available to you
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i915.modeset=1 video=LVDS-1:d"

So the above would direct video output to VGA port only.

My problem is solved, credit due to https://bbs.archlinux.org/viewtopic.php?id=145648 which in turn drew this solution from http://permalink.gmane.org/gmane.linux.mageia.devel/13667

What is i915.modeset=1 for?

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