Re: [culprit found] Re: [boot hang] 2.6.7-rc2, VIA VT8237

From: Andi Kleen
Date: Sat Jun 12 2004 - 09:03:19 EST


David Ford <david+challenge-response@xxxxxxxxxxxxx> writes:

> Culprit found. If CONFIG_IOMMU_DEBUG is enabled, the machine will
> hang on boot at the partition check when using the VIA driver.

The real culprit is buggy VIA silicon. Use this patch.

-Andi

---------------------------------------------------------------
Enable VIA softmmu workaround for iommu=force/IOMMU_DEBUG too

diff -u linux-2.6.7rc3-bk3/arch/x86_64/kernel/io_apic.c-o linux-2.6.7rc3-bk3/arch/x86_64/kernel/io_apic.c
--- linux-2.6.7rc3-bk3/arch/x86_64/kernel/io_apic.c-o 2004-06-11 03:02:42.000000000 +0200
+++ linux-2.6.7rc3-bk3/arch/x86_64/kernel/io_apic.c 2004-06-12 15:46:35.000000000 +0200
@@ -252,7 +252,8 @@
switch (vendor) {
case PCI_VENDOR_ID_VIA:
#ifdef CONFIG_GART_IOMMU
- if (end_pfn >= (0xffffffff>>PAGE_SHIFT) &&
+ if ((end_pfn >= (0xffffffff>>PAGE_SHIFT) ||
+ force_iommu) &&
!iommu_aperture_allowed) {
printk(KERN_INFO
"Looks like a VIA chipset. Disabling IOMMU. Overwrite with \"iommu=allowed\"\n");

-
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