VT-d and x2apic: broken resume after suspend to ram

Hi, I'm trying to fix a bug that is affecting me for more than two years now. It is happening in a Toshiba R830-10P notebook. I've filled a bug report: https://bugzilla.redhat.com/show_bug.cgi?id=787299 And recently asked for help on the LKML: https://lkml.org/lkml/2013/11/1/186 The issue is that trying to resume after suspending to ram freezes the computer. The resume starts well, but then it hangs. I found that this may be related to VT-d / x2apic. If I disable VT-d on the BIOS, suspend / resume works fine. If I enable VT-d and pass nox2apic as boot parameter to Kernel suspend and resume works fine. Any ideas on how to debug this issue without a serial port? Thanks! -- Peter