Comment 7 for bug 629711

Having learnt about the udevd anomaly, I repeated the bisection and found this as the potential culprit for my failure:

commit 7f8a85698f5c8a981641ec0bdf9926768786db9d
Author: Zhenyu Wang <email address hidden>
Date: Thu Apr 1 13:07:53 2010 +0800

    drm/i915: Add the support of memory self-refresh on Ironlake

    Update the self-refresh watermark for display plane/cursor and enable
    the memory self-refresh on Ironlake. The watermark is also updated for
    the active display plane.

    More than 1W idle power is saved on one Ironlake laptop after enabling
    memory self-refresh.