Hi Greg&all,
So a recent stable backport to fix rc6 on ilk (which is disabled by default and with dubious power savings at best, unlike rc6 on snb and later) totally blew up all over the place: https://bugzilla.kernel.org/show_bug.cgi?id=55291 https://lkml.org/lkml/2013/3/14/540
There might be more, I'm still recovering from mail floods due to traveling last week. I think the right course of action is to revert the offending patch (plus anything depending upon it) and give up on rc6 on ilk in 3.8 - too messy. All bug reports confirmed that 3.9-rc kernels work as expected. Upstream commits to revert:
15239099d7a7a9ecdc1ccb5b187ae4cda5488ff9 drm/i915: enable irqs earlier when resuming 52d7ecedac3f96fb562cb482c139015372728638 drm/i915: reorder setup sequence to have irqs for output setup
Cheers, Daniel