ACPI / sleep: Rework the handling of ACPI GPE wakeup from suspend-to-idle

The ACPI GPE wakeup from suspend-to-idle is currently based on using
the IRQF_NO_SUSPEND flag for the ACPI SCI, but that is problematic
for a couple of reasons.  First, in principle the ACPI SCI may be
shared and IRQF_NO_SUSPEND does not really work well with shared
interrupts.  Second, it may require the ACPI subsystem to special-case
the handling of device notifications depending on whether or not
they are received during suspend-to-idle in some places which would
lead to fragile code.  Finally, it's better the handle ACPI wakeup
interrupts consistently with wakeup interrupts from other sources.

For this reason, remove the IRQF_NO_SUSPEND flag from the ACPI SCI
and use enable_irq_wake()/disable_irq_wake() with it instead, which
requires two additional platform hooks to be added to struct
platform_freeze_ops.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 54da4a3fe65e..05a31b573fc3 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -14,6 +14,7 @@
 #include <linux/irq.h>
 #include <linux/dmi.h>
 #include <linux/device.h>
+#include <linux/interrupt.h>
 #include <linux/suspend.h>
 #include <linux/reboot.h>
 #include <linux/acpi.h>
@@ -626,6 +627,19 @@ static int acpi_freeze_begin(void)
         return 0;
 }
 
+static int acpi_freeze_prepare(void)
+{
+        acpi_enable_all_wakeup_gpes();
+        enable_irq_wake(acpi_gbl_FADT.sci_interrupt);
+        return 0;
+}
+
+static void acpi_freeze_restore(void)
+{
+        disable_irq_wake(acpi_gbl_FADT.sci_interrupt);
+        acpi_enable_all_runtime_gpes();
+}
+
 static void acpi_freeze_end(void)
 {
         acpi_scan_lock_release();
@@ -633,6 +647,8 @@ static void acpi_freeze_end(void)
 
 static const struct platform_freeze_ops acpi_freeze_ops = {
         .begin = acpi_freeze_begin,
+        .prepare = acpi_freeze_prepare,
+        .restore = acpi_freeze_restore,
         .end = acpi_freeze_end,
 };