Red Hat Bugzilla – Bug 499614
System locks up when booting with "intel_iommu=on" (BIOS bug?)
Last modified: 2009-05-14 10:40:05 EDT
Created attachment 342832 [details]
Captured kernel messages from the serial console
Description of problem:
When the kernel is booted with bootparam intel_iommu=on the system locks up.
Version-Release number of selected component (if applicable):
Always, also with different BIOS settings (e.g. Coherency="on/off")
Steps to Reproduce:
1. Intall F11-Preview
2. Reboot and edit in grub so that boot param intel_iommu=on is submitted
If you boot with params "rhgb quiet" you only see the cursor blinking in the upper left corner of the screen. If you boot without "rhgb quiet" then you see the messages that I captured in the attached file.
System should boot to runlevel 5.
Since the capture log also has a line
DMAR:Unknown DMAR structure type
U expect that the root cause of this bug can be somewhere within the BIOS. So I will contact BIOS development first to see if they can explain that. This is why this bug is currently set to low priority.
Can you build a kernel without CONFIG_INTR_REMAP to check whether it's DMA remapping or interrupt remapping that's causing the problem?
User reports that turning off legacy keyboard emulation in the BIOS fixes the hang. This seems to be a duplicate of bug 490477.
User reports an identical hang at 'starting udev', which needs to be investigated further.
*** This bug has been marked as a duplicate of bug 490477 ***
Need-Real, you have one of these?