This is a note to let you know that I've just added the patch titled
ACPI: PM: Fix device wakeup power reference counting error
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
acpi-pm-fix-device-wakeup-power-reference-counting-e.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1d09e3b0062423466cefbca032e6a71462db7a23
Author: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Date: Thu Nov 4 22:54:17 2021 +0100
ACPI: PM: Fix device wakeup power reference counting error
[ Upstream commit 452a3e723f75880757acf87b053935c43aa89f89 ]
Fix a device wakeup power reference counting error introduced by
commit a2d7b2e004af ("ACPI: PM: Fix sharing of wakeup power
resources") because of a coding mistake.
Fixes: a2d7b2e004af ("ACPI: PM: Fix sharing of wakeup power resources")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 4b42debeed455..c95eedd58f5bf 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -755,13 +755,11 @@ int acpi_disable_wakeup_device_power(struct acpi_device *dev)
mutex_lock(&acpi_device_lock);
- if (dev->wakeup.prepare_count > 1) {
- dev->wakeup.prepare_count--;
+ /* Do nothing if wakeup power has not been enabled for this device. */
+ if (dev->wakeup.prepare_count <= 0)
goto out;
- }
- /* Do nothing if wakeup power has not been enabled for this device. */
- if (!dev->wakeup.prepare_count)
+ if (--dev->wakeup.prepare_count > 0)
goto out;
err = acpi_device_sleep_wake(dev, 0, 0, 0);
