On Mon, 16 Oct 2017, 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. I'm curious: Why does the PCI bus type (and others) do this? Why doesn't it do what the driver says to do? Alan Stern
