On Tue, Dec 1, 2020 at 1:30 PM Furquan Shaikh <furquan@xxxxxxxxxx> wrote: > > When the system is powered off or rebooted, devices are not detached > from their PM domain. This results in ACPI PM not being invoked and > hence PowerResouce _OFF method not being invoked for any of the > devices. Because the ACPI power resources are not turned off in case > of poweroff and reboot, it violates the power sequencing requirements > which impacts the reliability of the devices over the lifetime of the > platform. This is currently observed on all Chromebooks using ACPI. > > In order to solve the above problem, this change detaches a device > from its PM domain whenever it is shutdown. This action is basically > analogous to ->remove() from driver model perspective. Detaching the > device from its PM domain ensures that the ACPI PM gets a chance to > turn off the power resources for the device thus complying with its > power sequencing requirements. > > Signed-off-by: Furquan Shaikh <furquan@xxxxxxxxxx> > --- > drivers/base/core.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index d661ada1518f..5823f1d719e1 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -23,6 +23,7 @@ > #include <linux/of_device.h> > #include <linux/genhd.h> > #include <linux/mutex.h> > +#include <linux/pm_domain.h> > #include <linux/pm_runtime.h> > #include <linux/netdevice.h> > #include <linux/sched/signal.h> > @@ -4057,6 +4058,8 @@ void device_shutdown(void) > dev->driver->shutdown(dev); > } > > + dev_pm_domain_detach(dev, true); > + > device_unlock(dev); > if (parent) > device_unlock(parent); > -- > 2.29.2.454.gaff20da3a2-goog > Hello, Gentle ping. Just checking if there are any comments. Thanks, Furquan
