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My Debian is Broken - Intel-IOMMU

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GPWR
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My Debian is Broken - Intel-IOMMU

#1 Post by GPWR »

Greetings.

Just installed a new GPU and my computer has been buggy for a few days following my attempts to make it work. Then my system crashed when rendering a video made in Kdenlive. Since then, Debian doesn't want to boot outside of emergency mode, and I get these two messages:

Code: Select all

DMAR: Failed to map dmar1
[...]
DMAR: [Firmware Bug]: Your BIOS is broken; DMAR reported address fed92000 returns all ones!
Before this happened, I had followed every single step of these instructions to disable Nouveau, because it was in the way for installing the Nvidia driver I needed for my GPU. From there, I installed the Nvidia driver from this file, which I downloaded from the GPU's manufacturer's website. As can be seen from that link, my GPU is a Zotac GeForce® GT 730 4GB Zone Edition [I used the "Linux Display Driver - x86_64-470.94 (GeForce 700)" file because my system's architecture is AMD64.] At first, SDDM wouldn't load because Nouveau was disabled, but it did work after I installed the Nvidia driver from the terminal and rebooted.

Now I found the following reading the kernel documentation:
If you encounter issues with graphics devices, you can try adding
option intel_iommu=igfx_off to turn off the integrated graphics engine.
If this fixes anything, please ensure you file a bug reporting the problem.
On the other hand, I found this solution on the Fedora forums:
A quick fix consists in replacing the boot kernel parameter ‘intel_iommu=on’ with ‘intel_iommu=pt’ “to set up pass through (PT) mode in context mapping entry”. DMAR is then disabled in the GNU/Linux kernel but KVM still benefits IOMMU and interrupt remapping.
I am planning on eventually using virtual machines to test software on my system, so the latter sounds more convenient. However, I wanted to know what a Debian user would recommend, and why.

Also, there are quite a few other errors and warnings in my log, but when I exported it to a text file and tried to read it from another PC, it was difficult to spot the errors because there is no highlighting as when viewing it with journalctl. The reason it's difficult for me to view it on my Debian system is that everything is in huge type, as described in this post.

Sunrat kindly suggested that I use the driver from the non-free repos to make things a little easier, but I was stupid and did it the hard way, because I wanted to learn the most possible from my experience. So I guess I'm getting what I asked for!

Thank you in advance for any help, and may God bless you.

Cheers.

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