Re: [stable] Suspend regression in stable kernel 2.6.27.4 on Mac mini Core Duo

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Thursday, 13 of November 2008, Tino Keitel wrote:
> On Wed, Nov 12, 2008 at 22:41:08 +0100, Rafael J. Wysocki wrote:
> > On Wednesday, 12 of November 2008, Tino Keitel wrote:
> > > On Wed, Nov 12, 2008 at 01:03:54 +0100, Rafael J. Wysocki wrote:
> > > 
> > > [...]
> > > 
> > > > Also, can you check this patch on top of 2.6.27.4 and see what happens?
> > > 
> > > With that patch, resume works (although I used 2.6.27.5 and not
> > > 2.6.27.5, if that matters).
> > 
> > It shouldn't really matter.
> > 
> > Thanks for testing and please send me the output of dmidecode.
> > It seems that blacklisting may be the only way to handle your box. :-(
> 
> Attached.

Please try the appended patch on top of the Linus' tree.

Thanks,
Rafael

---
 drivers/acpi/sleep/main.c |   40 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 39 insertions(+), 1 deletion(-)

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
@@ -104,6 +104,18 @@ void __init acpi_s4_no_nvs(void)
 	s4_no_nvs = true;
 }
 
+/*
+ * According to the ACPI specification the BIOS should make sure that ACPI is
+ * enabled and SCI_EN bit is set on wake-up from S1 - S3 sleep states.  Still,
+ * some BIOSes don't do that and therefore we use acpi_enable() to enable ACPI
+ * on such systems during resume.  Unfortunately that doesn't help in
+ * particularly pathological cases in which SCI_EN has to be set directly on
+ * resume, although the specification states very clearly that this flag is
+ * owned by the hardware.  The set_sci_en_on_resume variable will be set in such
+ * cases.
+ */
+static bool set_sci_en_on_resume;
+
 /**
  *	acpi_pm_disable_gpes - Disable the GPEs.
  */
@@ -249,7 +261,11 @@ static int acpi_suspend_enter(suspend_st
 	}
 
 	/* If ACPI is not enabled by the BIOS, we need to enable it here. */
-	acpi_enable();
+	if (set_sci_en_on_resume)
+		acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1);
+	else
+		acpi_enable();
+
 	/* Reprogram control registers and execute _BFS */
 	acpi_leave_sleep_state_prep(acpi_state);
 
@@ -337,6 +353,12 @@ static int __init init_old_suspend_order
 	return 0;
 }
 
+static int __init init_set_sci_en_on_resume(const struct dmi_system_id *d)
+{
+	set_sci_en_on_resume = true;
+	return 0;
+}
+
 static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
 	{
 	.callback = init_old_suspend_ordering,
@@ -354,6 +376,22 @@ static struct dmi_system_id __initdata a
 		DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
 		},
 	},
+	{
+	.callback = init_set_sci_en_on_resume,
+	.ident = "Apple MacBook 1,1",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "MacBook1,1"),
+		},
+	},
+	{
+	.callback = init_set_sci_en_on_resume,
+	.ident = "Apple MacMini 1,1",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "Macmini1,1"),
+		},
+	},
 	{},
 };
 #endif /* CONFIG_SUSPEND */