After installing Ubuntu Gnome 16.04.1 I started to notice the error message:
DMAR: Failed to map dmar0 al boot
It was some time that I noticed some slowdowns in the POST process, especially during the detection of my USB webcam
After some research online, I found the detailed analysis (made for a Fedora OS)
and I found out this message in my dmesg event log:
Your BIOS is broken; DMAR reported at address fed90000 returns all ones!
that appears only if the Intel VT(d) option is enabled in the BIOS.
As far as I understood from the a.m. post, unless there will be a new bios update, the situation cannot be solved. Unfortunately the latest bios is already installed and I seriously doubt new updates will come (my ASUS mobo is 3 or 4 years old now).
Now, since I sometimes use Virtualbox, I'd prefer to keep the intel VT(d) option enabled but I would like to avoid any mis-behavior of the USB peripherals (which happened in the past and now I'm inclined to explain with this bios-related issue)
I already tried to add the
iommu=soft option at the kernel boot-up but it did not work.
Do you have any suggestions to solve or workaround this issue?
Is there any chance that a previous bios will work? I already tested the last two...