ACPI PM: Replace wakeup.prepared with reference counter

The wakeup.prepared flag is used for marking devices that have the
wake-up power already enabled, so that the wake-up power is not
enabled twice in a row for the same device.  This assumes, however,
that device wake-up power will only be enabled once, while the device
is being prepared for a system-wide sleep transition, and the second
attempt is made by acpi_enable_wakeup_device_prep().

With the upcoming PCI wake-up rework this assumption will not hold
any more for PCI bridges and the root bridge whose wake-up power
may be enabled as a result of wake-up enable propagation from other
devices (eg. add-on devices that are not associated with any GPEs).
Thus, there may be many attempts to enable wake-up power on a PCI
bridge or the root bridge during a system power state transition
and it's better to replace wakeup.prepared with a reference counter.

Reviewed-by: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index c3ace75d57b4..1fa3ffb7c93b 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -248,7 +248,6 @@ struct acpi_device_perf {
 /* Wakeup Management */
 struct acpi_device_wakeup_flags {
         u8 valid:1;             /* Can successfully enable wakeup? */
-        u8 prepared:1;          /* Has the wake-up capability been enabled? */
         u8 run_wake:1;          /* Run-Wake GPE devices */
 };
 
@@ -263,6 +262,7 @@ struct acpi_device_wakeup {
         struct acpi_handle_list resources;
         struct acpi_device_wakeup_state state;
         struct acpi_device_wakeup_flags flags;
+        int prepare_count;
 };
 
 /* Device */