System locks up when idle and screen is blank

Problem:

System sometimes locks up when idle and screen is blank

Affected OS:

  • Fedora 19

Affected Models:

  • M521
  • C521

Affected Graphics Controller:

  • Intel HD4600

Details:

This problem is thought to be caused by a bug that is triggered when the GPU goes into a power saving mode.

Solution:

Disable GPU power saving by adding the following line to /etc/default/grub:

i915.i915_enable_rc6=0

Then regenerate the GRUB configuration:

# grub2-mkconfig -o /boot/grub2/grub.cfg

Reboot the system for the option to take effect. The current setting can be checked with the following command:

# cat /sys/module/i915/parameters/i915_enable_rc6
0