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Comment: 945GM crash, gentoo wiki, kernel boot parameter
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 * [[https://fedoraproject.org/wiki/Features/KernelModesetting|Fedora KMS page]]

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/modprobe.d/intel.conf :

options i915 modeset=1

At the next boot, the kernel should be handling modesetting. Alternatively, pass i915.modeset=1 to the kernel at boot, e.g. (in your grub configuration file):

kernel /some-kernel root=/dev/root i915.modeset=1

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