Hi Daniel, the patch does work, i.e., it turns off DMAR for the graphics card and alleviates the freezes when loading i915/kms.
However, still seeing random machine freezes with it (being consistent with the behavior I've experienced with intel_iommu=igfx_off). The patch + forcing RWBF is working, too. Interestingly, this version didn't randomly freeze yet, after more than 5 hours of uptime! I'll leave the box running until tomorrow to make sure I did stick around long enough. All those tested kernels were able to handle USB and PCI(e) devices. I still have to test turning off IOMMU in general and Intel IOMMU specifically. Will probably do this tomorrow. Thank you so far! :) Mihai
smime.p7s
Description: S/MIME Cryptographic Signature