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
From xserver-xorg-video-intel version 2:2.9.1-2, KMS is enabled by default on Linux, by the way of the file /etc/modprobe.d/i915-kms.conf. So from Squeeze on, no hand modification should be necessary anymore.
Known bugs
- 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.
- If you launch your kernel with a vga=xxx option on the boot line, it will fail (black screen).
- 945GM
Enabling KMS on this chipset may cause a GPU crash: (link)
Resources
KMS with the Intel GMA at the Gentoo Wiki