On Mon, Aug 26, 2019 at 11:31:08AM +0300, Sakari Ailus wrote: > Allow drivers and firmware tell ACPI that there's no need to power on a > device for probe. This requires both a hint from the firmware as well as > an indication from a driver to leave the device off. > > Signed-off-by: Sakari Ailus <[email protected]> > --- > drivers/acpi/device_pm.c | 15 +++++++++++++-- > include/linux/device.h | 7 +++++++ > 2 files changed, 20 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c > index f616b16c1f0be..adcdf78ce4de8 100644 > --- a/drivers/acpi/device_pm.c > +++ b/drivers/acpi/device_pm.c > @@ -1276,7 +1276,12 @@ static void acpi_dev_pm_detach(struct device *dev, > bool power_off) > if (adev && dev->pm_domain == &acpi_general_pm_domain) { > dev_pm_domain_set(dev, NULL); > acpi_remove_pm_notifier(adev); > - if (power_off) { > + if (power_off > +#ifdef CONFIG_PM > + && !(dev->driver->probe_low_power && > + device_property_present(dev, "probe-low-power")) > +#endif > + ) { > /* > * If the device's PM QoS resume latency limit or flags > * have been exposed to user space, they have to be > @@ -1324,7 +1329,13 @@ int acpi_dev_pm_attach(struct device *dev, bool > power_on) > > acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func); > dev_pm_domain_set(dev, &acpi_general_pm_domain); > - if (power_on) { > + > + if (power_on > +#ifdef CONFIG_PM > + && !(dev->driver->probe_low_power && > + device_property_present(dev, "probe-low-power")) > +#endif > + ) { > acpi_dev_pm_full_power(adev); > acpi_device_wakeup_disable(adev); > } > diff --git a/include/linux/device.h b/include/linux/device.h > index 6717adee33f01..4bc0ea4a3201a 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -248,6 +248,12 @@ enum probe_type { > * @owner: The module owner. > * @mod_name: Used for built-in modules. > * @suppress_bind_attrs: Disables bind/unbind via sysfs. > + * @probe_low_power: The driver supports its probe function being called > while > + * the device is in a low power state, independently of the > + * expected behaviour on combination of a given bus and > + * firmware interface etc. The driver is responsible for > + * powering the device on using runtime PM in such case. > + * This configuration has no effect if CONFIG_PM is disabled. > * @probe_type: Type of the probe (synchronous or asynchronous) to use. > * @of_match_table: The open firmware table. > * @acpi_match_table: The ACPI match table. > @@ -285,6 +291,7 @@ struct device_driver { > const char *mod_name; /* used for built-in modules */ > > bool suppress_bind_attrs; /* disables bind/unbind via sysfs */ > + bool probe_low_power;
Ick, no, this should be a bus-specific thing to handle such messed up hardware. Why polute this in the driver core? thanks, greg k-h
