Description of problem: Having Calgary IOMMU enabled hangs X. Version-Release number of selected component (if applicable): How reproducible: Install 2.6.18-1.2717 or later with X. Steps to Reproduce: 1. Turn on machine and see it hang Actual results: Hang Expected results: Not hang Additional info:
Fix is to fix the radeon and the kernel to work nicely together. That is not going to happend for RHEL5. The workaround is to pass 'iommu=soft' or disable in the build CONFIG_CALGARY_IOMMU as so: [root@ibm-x232 SOURCES]grep "CALGARY" kernel-2.6.18-* kernel-2.6.18-x86_64.config:# CONFIG_CALGARY_IOMMU is not set kernel-2.6.18-x86_64-kdump.config:# CONFIG_CALGARY_IOMMU is not set kernel-2.6.18-x86_64-xen.config:CONFIG_CALGARY_IOMMU=y The fix is as follow: --- kernel-2.6.18-x86_64.config.orig 2006-10-05 15:33:57.000000000 -0400 +++ kernel-2.6.18-x86_64.config 2006-10-11 13:48:31.000000000 -0400 @@ -2903,7 +2903,7 @@ CONFIG_DEBUG_RODATA=y CONFIG_MICROCODE=m CONFIG_SWIOTLB=y -CONFIG_CALGARY_IOMMU=y +# CONFIG_CALGARY_IOMMU is not set CONFIG_X86_PM_TIMER=y CONFIG_EDD=m CONFIG_PCI_BIOS=y --- kernel-2.6.18-x86_64-kdump.config.orig 2006-10-05 15:33:57.000000000 -0400 +++ kernel-2.6.18-x86_64-kdump.config 2006-10-11 13:48:42.000000000 -0400 @@ -2903,7 +2903,7 @@ CONFIG_DEBUG_RODATA=y CONFIG_MICROCODE=m CONFIG_SWIOTLB=y -CONFIG_CALGARY_IOMMU=y +# CONFIG_CALGARY_IOMMU is not set CONFIG_X86_PM_TIMER=y CONFIG_EDD=m CONFIG_PCI_BIOS=y
Patch posted for inclusion in RHEL5.
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux release. Product Management has requested further review of this request by Red Hat Engineering. This request is not yet committed for inclusion in release.
in kernel-2.6.18-1.2726.el5
QE ack for RHEL5B2 according to section 21a of the release criteria.
I have to NACK my patch. The new radeon driver (xorg-x11-drv-ati-6.6.2-4.1.el5.src.rpm) fixes this problem without disabling CALGARY_IOMMU.
Fix is in RH BZ #197992 *** This bug has been marked as a duplicate of 197992 ***