Differences between revisions 9 and 10
Revision 9 as of 2009-05-08 00:01:42
Size: 1258
Editor: ?dsalt
Comment: Minor corrections.
Revision 10 as of 2009-05-10 21:01:25
Size: 1471
Editor: ?dsalt
Comment: Add a brief description of what KMS is.
Deletions are marked like this. Additions are marked like this.
Line 2: Line 2:

This provides faster mode switching for X and console. It also provides native-resolution VTs on some laptops & netbooks which, prior to this, would use some standard mode, e.g. 800×600 on a 1024×600 panel.
Line 5: Line 7:
 * a kernel image >= 2.6.29 (in Sid since 2009-04-04)  * a kernel image 2.6.29 (in Sid since 2009-04-04)

KernelModesetting

This provides faster mode switching for X and console. It also provides native-resolution VTs on some laptops & netbooks which, prior to this, would use some standard mode, e.g. 800×600 on a 1024×600 panel.

To enable Kernel Mode Setting, also known as KMS, you need:

  • a kernel image ≥ 2.6.29 (in Sid since 2009-04-04)
  • supported graphics card

Intel

i915

To enable KMS on i915 hardware, just add the following lines to /etc/initramfs-tools/modules :

# Enable Kernel Modesetting
intel_agp
drm
i915 modeset=1

And regenerate your initramfs:

# update-initramfs -k `uname -r` -u

At the next boot, the kernel should be handling modesetting.

Known bugs

  • pm-utils
  • vbetool
    • Running this will cause X to fail to start up (black screen except for a static cursor at the top left, can't switch vt), and may cause other problems. (This is a kernel bug.) To avoid this, set SAVE_VBE_STATE=false in /etc/default/acpi-support.

  • linux-2.6
    • Do not load any framebuffer drivers other than inteldrmfb (which is provided by i915) if you enable KMS, else you will probably see hard lockups when trying to start X.
    • xserver-xorg-video-intel 2.7.0 doesn't work fine with linux-image 2.6.29-1. You can fetch a fixed kernel from buildserver sid snapshots (see DebianKernel)