This is a note to let you know that I've just added the patch titled
efi: Clear EFI_RUNTIME_SERVICES rather than EFI_BOOT by "noefi" boot
parameter
to the 3.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
efi-clear-efi_runtime_services-rather-than-efi_boot-by-noefi-boot-parameter.patch
and it can be found in the queue-3.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 1de63d60cd5b0d33a812efa455d5933bf1564a51 Mon Sep 17 00:00:00 2001
From: Satoru Takeuchi <[email protected]>
Date: Thu, 14 Feb 2013 09:12:52 +0900
Subject: efi: Clear EFI_RUNTIME_SERVICES rather than EFI_BOOT by "noefi" boot
parameter
From: Satoru Takeuchi <[email protected]>
commit 1de63d60cd5b0d33a812efa455d5933bf1564a51 upstream.
There was a serious problem in samsung-laptop that its platform driver is
designed to run under BIOS and running under EFI can cause the machine to
become bricked or can cause Machine Check Exceptions.
Discussion about this problem:
https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557
https://bugzilla.kernel.org/show_bug.cgi?id=47121
The patches to fix this problem:
efi: Make 'efi_enabled' a function to query EFI facilities
83e68189745ad931c2afd45d8ee3303929233e7f
samsung-laptop: Disable on EFI hardware
e0094244e41c4d0c7ad69920681972fc45d8ce34
Unfortunately this problem comes back again if users specify "noefi" option.
This parameter clears EFI_BOOT and that driver continues to run even if running
under EFI. Refer to the document, this parameter should clear
EFI_RUNTIME_SERVICES instead.
Documentation/kernel-parameters.txt:
===============================================================================
...
noefi [X86] Disable EFI runtime services support.
...
===============================================================================
Documentation/x86/x86_64/uefi.txt:
===============================================================================
...
- If some or all EFI runtime services don't work, you can try following
kernel command line parameters to turn off some or all EFI runtime
services.
noefi turn off all EFI runtime services
...
===============================================================================
Signed-off-by: Satoru Takeuchi <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Cc: Matt Fleming <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
arch/x86/platform/efi/efi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -87,7 +87,7 @@ EXPORT_SYMBOL(efi_enabled);
static int __init setup_noefi(char *arg)
{
- clear_bit(EFI_BOOT, &x86_efi_facility);
+ clear_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
return 0;
}
early_param("noefi", setup_noefi);
Patches currently in stable-queue which might be from
[email protected] are
queue-3.7/efi-clear-efi_runtime_services-rather-than-efi_boot-by-noefi-boot-parameter.patch
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