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pm: acpi hibernation: utilize hardware signature

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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.

[[email protected]: build fix]
Signed-off-by: Shaohua Li <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Len Brown <[email protected]>
Acked-by: Pavel Machek <[email protected]>
Cc: <[email protected]>
Cc: Shaohua Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Shaohua Li 2008-07-23 21:28:41 -07:00 • committed by Linus Torvalds
commit bdfe6b7c68
4 changed files with 30 additions and 1 deletions
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22
drivers/acpi/sleep/main.c
View file

@ -283,6 +283,15 @@ static struct platform_suspend_ops acpi_suspend_ops_old = {
#endif /* CONFIG_SUSPEND */
#ifdef CONFIG_HIBERNATION
static unsigned long s4_hardware_signature;
static struct acpi_table_facs *facs;
static bool nosigcheck;
void __init acpi_no_s4_hw_signature(void)
{
nosigcheck = true;
}
static int acpi_hibernation_begin(void)
{
acpi_target_sleep_state = ACPI_STATE_S4;
@ -316,6 +325,12 @@ static void acpi_hibernation_leave(void)
acpi_enable();
/* Reprogram control registers and execute _BFS */
acpi_leave_sleep_state_prep(ACPI_STATE_S4);
/* Check the hardware signature */
if (facs && s4_hardware_signature != facs->hardware_signature) {
printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
"cannot resume!\n");
panic("ACPI S4 hardware signature mismatch");
}
}
static void acpi_pm_enable_gpes(void)
@ -544,6 +559,13 @@ int __init acpi_sleep_init(void)
&acpi_hibernation_ops_old : &acpi_hibernation_ops);
sleep_states[ACPI_STATE_S4] = 1;
printk(" S4");
if (!nosigcheck) {
acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
(struct acpi_table_header **)&facs);
if (facs)
s4_hardware_signature =
facs->hardware_signature;
}
}
#endif
status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);