On Thu, Nov 4, 2021 at 10:54 PM Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote:
>
> 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.
Tested now, so applying as 5.16-rc material.
> ---
> 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);
>
>
>
>
