On Sun, 14 Mar 2010, Rafael J. Wysocki wrote: > > You know, maybe we should allow bus types to use both the old and new > > interfaces. It would make life easier for other subsystems in addition > > to i2c. > > > > This doesn't mean that the core would end up calling two sets of > > suspend routines. If the bus type uses legacy routines then all the > > non-runtime entries in the pm_ops structure would be empty. > > > > The changes to the PM core necessary to do this are quite small. > > Not really. The detection that the particular callback is not present happens > in pm_op(), while the decision which framework to use is made at the > device_[suspend|resume]() level. All you have to do is change the "else if" lines in device_[suspend|resume]() to "if". > > Does it seem like a reasonable thing to do? > > Well, if someone spends time on implementing new callbacks for a bus type, > writing them in such a way that they will call the "legacy" callbacks from > drivers if necessary is not really a big deal IMO. Sure. But suppose you _don't_ want to spend the time implementing new callbacks to replace the existing legacy suspend and resume methods, whereas you _do_ want to implement runtime PM. Runtime PM forces the bus type to have a pm_ops member, which as you point out, will prevent the legacy methods from being called. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
