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-rw-r--r--drivers/acpi/sleep.c26
1 files changed, 21 insertions, 5 deletions
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 4b8454f26ca1..a60ff5dfed3a 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -874,11 +874,11 @@ static inline void acpi_sleep_syscore_init(void) {}
#ifdef CONFIG_HIBERNATION
static unsigned long s4_hardware_signature;
static struct acpi_table_facs *facs;
-static bool nosigcheck;
+static int sigcheck = -1; /* Default behaviour is just to warn */
-void __init acpi_no_s4_hw_signature(void)
+void __init acpi_check_s4_hw_signature(int check)
{
- nosigcheck = true;
+ sigcheck = check;
}
static int acpi_hibernation_begin(pm_message_t stage)
@@ -1004,12 +1004,28 @@ static void acpi_sleep_hibernate_setup(void)
hibernation_set_ops(old_suspend_ordering ?
&acpi_hibernation_ops_old : &acpi_hibernation_ops);
sleep_states[ACPI_STATE_S4] = 1;
- if (nosigcheck)
+ if (!sigcheck)
return;
acpi_get_table(ACPI_SIG_FACS, 1, (struct acpi_table_header **)&facs);
- if (facs)
+ if (facs) {
+ /*
+ * s4_hardware_signature is the local variable which is just
+ * used to warn about mismatch after we're attempting to
+ * resume (in violation of the ACPI specification.)
+ */
s4_hardware_signature = facs->hardware_signature;
+
+ if (sigcheck > 0) {
+ /*
+ * If we're actually obeying the ACPI specification
+ * then the signature is written out as part of the
+ * swsusp header, in order to allow the boot kernel
+ * to gracefully decline to resume.
+ */
+ swsusp_hardware_signature = facs->hardware_signature;
+ }
+ }
}
#else /* !CONFIG_HIBERNATION */
static inline void acpi_sleep_hibernate_setup(void) {}