lkml.org 
[lkml]   [2006]   [Dec]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[patch] x86_64: fix boot hang caused by CALGARY_IOMMU_ENABLED_BY_DEFAULT
Subject: [patch] x86_64: fix boot hang caused by CALGARY_IOMMU_ENABLED_BY_DEFAULT
From: Ingo Molnar <mingo@elte.hu>

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 <mingo@elte.hu>
---
arch/x86_64/Kconfig | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

Index: linux/arch/x86_64/Kconfig
===================================================================
--- linux.orig/arch/x86_64/Kconfig
+++ linux/arch/x86_64/Kconfig
@@ -495,14 +495,13 @@ 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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2006-12-20 11:35    [W:0.186 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site