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Old 04-21-12, 01:31 PM   #33
meralias
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Join Date: Apr 2012
Posts: 2
Default Re: [BUG REPORT] 260.19.36 64-bit Linux driver conflicts with AMD 890FX IOMMU

Quote:
Originally Posted by alan242 View Post
"iommu=pt" allows my system to boot too. But I'm not sure the IOMMU is being used fully when this parameter is specified. See the notes on this patchset http://thread.gmane.org/gmane.linux.kernel/885604.
If I'm reading the notes there correctly, the 'pt' option means that all devices are registered to a special domain that allows them to access all system memory, unless something else comes along later and moves them into a different domain. This makes me think that the driver isn't registering something correctly and so when the card tries to initialize, it is trying to access memory that it doesn't have the right privileges to (something that I had already wondered about having saw a page fault error just before the initialization fails)

Note: It also looks like Nvidia are only supporting a small subset of devices for this type of functionality anyway, based on the details here: http://wiki.xen.org/wiki/Xen_VGA_Pas...splay_adapters
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