[80/81] efi: Clear EFI_RUNTIME_SERVICES rather than EFI_BOOT by "noefi" boot parameter

Submitted by Herton Ronaldo Krzesinski on Feb. 19, 2013, 6:49 p.m.


Message ID 1361299784-8830-81-git-send-email-herton.krzesinski@canonical.com
State New
Headers show

Commit Message

Herton Ronaldo Krzesinski Feb. 19, 2013, 6:49 p.m. -stable review patch.  If anyone has any objections, please let me know.


From: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>

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:

    The patches to fix this problem:
    efi: Make 'efi_enabled' a function to query EFI facilities

    samsung-laptop: Disable on EFI hardware

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


Patch hide | download patch | download mbox

	noefi		[X86] Disable EFI runtime services support.

- 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
	noefi		turn off all EFI runtime services

Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Link: http://lkml.kernel.org/r/511C2C04.2070108@jp.fujitsu.com
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
 arch/x86/platform/efi/efi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 6fcd4ad..3705bb0 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -86,7 +86,7 @@  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);