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Old 01-12-12, 05:21 AM   #3
cova
Registered User
 
Join Date: Mar 2005
Posts: 25
Thumbs up Re: Linux kernel 3.2.0 freeze with 290.10

Quote:
Originally Posted by FishB8 View Post
Same issue, also a Gentoo system. Doesn't cause problem on my i7 laptop. Freezes up on my Phenom II desktop.

No issues if I prevent xdm from starting. (Nvidia module loads and unloads)

My primary suspect is the IOMMU in my desktop.
You are right on the spot

I've done some tests playing with IOMMU support in my kernel.

The option that causes issues seems to be
CONFIG_INTEL_IOMMU_DEFAULT_ON

If set, the driver locks.

Full IOMMU working conf:

cova@calvin ~ $ zcat /proc/config.gz | grep IOMMU
# CONFIG_CALGARY_IOMMU is not set
CONFIG_IOMMU_HELPER=y
CONFIG_IOMMU_API=y
CONFIG_IOMMU_SUPPORT=y
# CONFIG_AMD_IOMMU is not set
CONFIG_INTEL_IOMMU=y
# CONFIG_INTEL_IOMMU_DEFAULT_ON is not set
CONFIG_INTEL_IOMMU_FLOPPY_WA=y
# CONFIG_IOMMU_STRESS is not set


Interesting this message from kernel, in working situation:

IOMMU 0: reg_base_addr fed90000 ver 1:0 cap c9008020e30272 ecap 1000
IOMMU 1: reg_base_addr fed93000 ver 1:0 cap c9008020630272 ecap 1000
DMAR: BIOS has allocated no shadow GTT; disabling IOMMU for graphics


Many thanks for the hint!!!
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