On Wednesday, 7 of May 2008, Pavel Machek wrote:
> Hi!
Hi,
> > > > +static int __init acpi_s4_nosigcheck(char *str)
> > > > +{
> > > > + nosigcheck = true;
> > > > + return 1;
> > > > +}
> > > > +__setup("acpi_s4_nosigcheck", acpi_s4_nosigcheck);
> > > > +
> > >
> > > Needs a patch to Documentation/ , too.
> >
> > Yes, thanks.
> >
> > > > + /* Check the hardware signature */
> > > > + if (facs && s4_hardware_signature != facs->hardware_signature)
> > >
> > > do you need && !nosigcheck here ?
> >
> > No, facs is NULL if !nosigcheck.
>
> Aha, ook. You can add my ACK when you add the Documentation/.
Corrected patch is appended.
Thanks,
Rafael
---
From: Shaohua Li <shaohua.li@xxxxxxxxx>
ACPI defines a hardware signature. BIOS calculates the signature
according to hardware configure, if hardware changes, the signature
will change, in this case, S4 resume should fail.
[rjw: The kernel command line switch acpi_s4_nosigcheck is added for
systems on which this mechanism is broken.]
Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx>
Acked-by: Pavel Machek <pavel@xxxxxxx>
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
Documentation/kernel-parameters.txt | 5 +++++
drivers/acpi/sleep/main.c | 24 ++++++++++++++++++++++++
2 files changed, 29 insertions(+)
Index: linux-2.6/drivers/acpi/sleep/main.c
===================================================================
--- linux-2.6.orig/drivers/acpi/sleep/main.c
+++ linux-2.6/drivers/acpi/sleep/main.c
@@ -255,6 +255,17 @@ static struct dmi_system_id __initdata a
#endif /* CONFIG_SUSPEND */
#ifdef CONFIG_HIBERNATION
+static unsigned long s4_hardware_signature;
+static struct acpi_table_facs *facs;
+static bool nosigcheck;
+
+static int __init acpi_s4_nosigcheck(char *str)
+{
+ nosigcheck = true;
+ return 1;
+}
+__setup("acpi_s4_nosigcheck", acpi_s4_nosigcheck);
+
static int acpi_hibernation_begin(void)
{
acpi_target_sleep_state = ACPI_STATE_S4;
@@ -301,6 +312,12 @@ 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_hibernation_finish(void)
@@ -501,6 +518,13 @@ int __init acpi_sleep_init(void)
hibernation_set_ops(&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);
Index: linux-2.6/Documentation/kernel-parameters.txt
===================================================================
--- linux-2.6.orig/Documentation/kernel-parameters.txt
+++ linux-2.6/Documentation/kernel-parameters.txt
@@ -152,6 +152,11 @@ and is between 256 and 4096 characters.
s3_beep is for debugging; it makes the PC's speaker beep
as soon as the kernel's real-mode entry point is called.
+ acpi_s4_nosigcheck [HW,ACPI] S4 hardware signature
+ ACPI will ignore the S4 hardware signature
+ default: The hardware signature is checked during
+ resume from S4.
+
acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Format: { level | edge | high | low }
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