Thank you for getting back to me. On Mon, 20 Jul 2020, Mika Westerberg wrote: > It is done on purpose. The BIOS generates new UUID every boot. I see. This leads to a couple of follow-on questions, then: There are two "competing" Linux packages for controlling/admining TB, "bolt" (which includes "boltctl") and "thunderbolt-tools" (which includes "tbtadm". I used to have both installed but I think they sometimes get in each other's way and settled on "thunderbolt-tools" as "bolt" was leaving large numbers of UUID-related files over time. - Do you have a preference for either? I've noticed that I can't seem to get IOMMU protection unless I boot with Secure Boot on in my BIOS (which I never use, as I don't sign my own kernels). IOMMU/DMAR is on in my kernel. - Is there any way to force this, or is this expected? I don't get the "iommu_dma_protection" set on my controllers either. Finally, every now and then on a reboot, my TB dock "flaps" (repeatedly connects and disconnects) and I have to either connect/reconnect the TB3 cable, or initate a power-off. I suspect this is a BIOS bug (I also have to set "intel_iommu=igfx_off" otherwise I get "DMA Hardware is malfunctioning" errors on power-down (or hibernate)). - Have you seen this before or have any ideas? Thanks, -Kenny -- Kenneth R. Crudup Sr. SW Engineer, Scott County Consulting, Orange County CA
