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authorShaohua Li <shaohua.li@intel.com>2008-07-23 21:28:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 10:47:24 -0700
commitbdfe6b7c681669148dae4db27eb24ee5408ba371 (patch)
tree644b84a7e4a329a635d9a9bc02102424cfb616e2 /arch
parent2f15fc4bdf91eb399da3f47a09c55831d9f22826 (diff)
pm: acpi hibernation: utilize hardware signature
ACPI defines a hardware signature. BIOS calculates the signature according to hardware configure and if hardware changes while hibernated, the signature will change. In that case, S4 resume should fail. Still, there may be systems on which this mechanism does not work correctly, so it is better to provide a workaround for them. For this reason, add a new switch to the acpi_sleep= command line argument allowing one to disable hardware signature checking. [shaohua.li@intel.com: build fix] Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Andi Kleen <andi@firstfloor.org> Cc: Len Brown <lenb@kernel.org> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: <Valdis.Kletnieks@vt.edu> Cc: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/acpi/sleep.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index a3ddad18aaa3..fa2161d5003b 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -150,6 +150,10 @@ static int __init acpi_sleep_setup(char *str)
acpi_realmode_flags |= 2;
if (strncmp(str, "s3_beep", 7) == 0)
acpi_realmode_flags |= 4;
+#ifdef CONFIG_HIBERNATION
+ if (strncmp(str, "s4_nohwsig", 10) == 0)
+ acpi_no_s4_hw_signature();
+#endif
if (strncmp(str, "old_ordering", 12) == 0)
acpi_old_suspend_ordering();
str = strchr(str, ',');