http://bugzilla.kernel.org/show_bug.cgi?id=11714
------- Comment #49 from [EMAIL PROTECTED] 2008-11-01 18:58 ------- Update: On further investigation, I found some additional relevant IOMMU info in my dmesg output: [ 0.490101] PCI-DMA: Disabling AGP. [ 0.490553] PCI-DMA: aperture base @ 20000000 size 65536 KB [ 0.490553] PCI-DMA: using GART IOMMU. [ 0.490553] PCI-DMA: Reserving 64MB of IOMMU area in the AGP aperture So, my AGP is being disabled by the kernel and GART IOMMU is being used: I don't know if that is the correct type. I notice that there are several types in the boot-options.txt document (which appears to have been deleted from the 2.6.26 documentation? http://www.linuxhq.com/kernel/v2.6/27/Documentation/x86_64/boot-options.txt). I then found a (annoyingly bloated) thread in a forum which provided a work around to the IOMMU problem for a very similar set-up to mine (amd64, asus motherboard, pci express, my agp getting disabled by the kernel). The workaround is to use the iommu=noaperture boot option (http://www.linuxquestions.org/questions/showthread.php?p=3173751#post3173751). When I do this I still get a kernel panic. However, the lines: Aperture pointing to e820 RAM. Ignoring. Your BIOS doesn't leave a memory aperture hole. Please enable the IOMMU option in the BIOS setup. This costs you 64 MB of RAM. no longer appear at the start. Instead, the kernel panic starts directly with BUG: unable to handle kernel NULL pointer dereference at 00000000 So, it looks like the IOMMU messages might not be the cause of the kernel panic after all and their appearance might be the result of a separate bug in the kernel that doesn't recognise that it doesn't need to create a memory aperture when agp is disabled. So, I am still none the wiser. I created an account with ASUS support and sent them a support message on the 18 October. They said they would try to get back to me within 24 hours and that if it took longer than 48 hours to reply my query would automatically become a 'first priority' but I still haven't received a reply yet. -- Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is. ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ acpi-bugzilla mailing list acpi-bugzilla@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla
