From a9622f6219ce58faba1417743bf3078501eb3434 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 20 Dec 2006 11:28:46 +0100 Subject: [PATCH] [PATCH] x86_64: fix boot hang caused by CALGARY_IOMMU_ENABLED_BY_DEFAULT one of my boxes didnt boot the 2.6.20-rc1-rt0 kernel rpm, it hung during early bootup. After an hour or two of happy debugging i narrowed it down to the CALGARY_IOMMU_ENABLED_BY_DEFAULT option, which was freshly added to 2.6.20 via the x86_64 tree and /enabled by default/. commit bff6547bb6a4e82c399d74e7fba78b12d2f162ed claims: [PATCH] Calgary: allow compiling Calgary in but not using it by default This patch makes it possible to compile Calgary in but not use it by default. In this mode, use 'iommu=calgary' to activate it. but the change does not actually practice it: config CALGARY_IOMMU_ENABLED_BY_DEFAULT bool "Should Calgary be enabled by default?" default y depends on CALGARY_IOMMU help Should Calgary be enabled by default? if you choose 'y', Calgary will be used (if it exists). If you choose 'n', Calgary will not be used even if it exists. If you choose 'n' and would like to use Calgary anyway, pass 'iommu=calgary' on the kernel command line. If unsure, say Y. it's both 'default y', and says "If unsure, say Y". Clearly not a typo. disabling this option makes my box boot again. The patch below fixes the Kconfig entry. Grumble. Signed-off-by: Ingo Molnar Signed-off-by: Linus Torvalds --- arch/x86_64/Kconfig | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig index d4275537b25..ef667245569 100644 --- a/arch/x86_64/Kconfig +++ b/arch/x86_64/Kconfig @@ -480,14 +480,13 @@ config CALGARY_IOMMU config CALGARY_IOMMU_ENABLED_BY_DEFAULT bool "Should Calgary be enabled by default?" - default y depends on CALGARY_IOMMU help - Should Calgary be enabled by default? if you choose 'y', Calgary + Should Calgary be enabled by default? If you choose 'y', Calgary will be used (if it exists). If you choose 'n', Calgary will not be used even if it exists. If you choose 'n' and would like to use Calgary anyway, pass 'iommu=calgary' on the kernel command line. - If unsure, say Y. + If unsure, say N. # need this always selected by IOMMU for the VIA workaround config SWIOTLB -- 2.20.1