On Thursday, November 4, 2021 6:21:51 PM CET Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> Fix a device wakeup power reference counting error introduced by
> commit a2d7b2e004af ("ACPI: PM: Fix sharing of wakeup power
> resources").
>
> Fixes: a2d7b2e004af ("ACPI: PM: Fix sharing of wakeup power resources")
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> ---
> drivers/acpi/power.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> Index: linux-pm/drivers/acpi/power.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/power.c
> +++ linux-pm/drivers/acpi/power.c
> @@ -757,10 +757,8 @@ int acpi_disable_wakeup_device_power(str
>
> mutex_lock(&acpi_device_lock);
>
> - if (dev->wakeup.prepare_count > 1) {
> + if (dev->wakeup.prepare_count >= 1)
> dev->wakeup.prepare_count--;
> - goto out;
> - }
>
> /* Do nothing if wakeup power has not been enabled for this device. */
> if (!dev->wakeup.prepare_count)
This is still not good. It should be something like the patch below, but I
need to test that one.
---
From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Subject: [PATCH v2] ACPI: PM: Fix device wakeup power reference counting error
Fix a device wakeup power reference counting error introduced by
commit a2d7b2e004af ("ACPI: PM: Fix sharing of wakeup power
resources").
Fixes: a2d7b2e004af ("ACPI: PM: Fix sharing of wakeup power resources")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
-> v2: Actually disable wakeup power when the reference count becomes zero.
---
drivers/acpi/power.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
Index: linux-pm/drivers/acpi/power.c
===================================================================
--- linux-pm.orig/drivers/acpi/power.c
+++ linux-pm/drivers/acpi/power.c
@@ -757,13 +757,11 @@ int acpi_disable_wakeup_device_power(str
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);
