• I
    [PATCH] x86_64: fix boot hang caused by CALGARY_IOMMU_ENABLED_BY_DEFAULT · a9622f62
    Ingo Molnar 提交于
    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 bff6547b 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: NIngo Molnar <mingo@elte.hu>
    Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
    a9622f62
Kconfig 19.7 KB