On Fri, Oct 20, 2017 at 01:11:22PM +0200, Rafael J. Wysocki wrote: > On Thursday, October 19, 2017 9:33:15 AM CEST Greg Kroah-Hartman wrote: > > On Thu, Oct 19, 2017 at 01:17:31AM +0200, Rafael J. Wysocki wrote: > > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > > > > > The motivation for this change is to provide a way to work around > > > a problem with the direct-complete mechanism used for avoiding > > > system suspend/resume handling for devices in runtime suspend. > > > > > > The problem is that some middle layer code (the PCI bus type and > > > the ACPI PM domain in particular) returns positive values from its > > > system suspend ->prepare callbacks regardless of whether the driver's > > > ->prepare returns a positive value or 0, which effectively prevents > > > drivers from being able to control the direct-complete feature. > > > Some drivers need that control, however, and the PCI bus type has > > > grown its own flag to deal with this issue, but since it is not > > > limited to PCI, it is better to address it by adding driver flags at > > > the core level. > > > > > > To that end, add a driver_flags field to struct dev_pm_info for flags > > > that can be set by device drivers at the probe time to inform the PM > > > core and/or bus types, PM domains and so on on the capabilities and/or > > > preferences of device drivers. Also add two static inline helpers > > > for setting that field and testing it against a given set of flags > > > and make the driver core clear it automatically on driver remove > > > and probe failures. > > > > > > Define and document two PM driver flags related to the direct- > > > complete feature: NEVER_SKIP and SMART_PREPARE that can be used, > > > respectively, to indicate to the PM core that the direct-complete > > > mechanism should never be used for the device and to inform the > > > middle layer code (bus types, PM domains etc) that it can only > > > request the PM core to use the direct-complete mechanism for > > > the device (by returning a positive value from its ->prepare > > > callback) if it also has been requested by the driver. > > > > > > While at it, make the core check pm_runtime_suspended() when > > > setting power.direct_complete so that it doesn't need to be > > > checked by ->prepare callbacks. > > > > > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > > > Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > Thanks! > > Does it also apply to the other patches in the series? > > I'd like to queue up the core patches for 4.15 as they are specifically > designed to only affect the drivers that actually set the flags, so there > shouldn't be any regression resulting from them, and I'd like to be > able to start using the flags in drivers going forward. Yes, sorry, I thought I acked them, but you are right, I didn't: Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> for all of them please. thanks, greg k-h
