[CC: list trimmed] On Tue, 31 Jul 2012, Rafael J. Wysocki wrote: > Now it occured to me that perhaps we don't need the current asynchronous > pm_runtime_get() at all. The usefulness of it is quite questionable, because > either we want to resume the device immediately, for which pm_runtime_get_sync() > should be used, or we just want to bump up the usage counter, in which cases > pm_runtime_get_noresume() should always be sufficient. I fail to see any > particularly compelling use case for pm_runtime_get() doing an asynchronous > resume at the moment, but perhaps that's just me. There are indeed valid uses for pm_runtime_get(). We are forced to use it in non-sleepable contexts when we want to resume the device as quickly as possible. Example: a driver receives an I/O request from an interrupt handler. > However, I receive reports of people using pm_runtime_get() where they really > should use pm_runtime_get_sync(), so I wonder if we can simply rename > pm_runtime_get_sync() as pm_runtime_get() and drop the asynchronous version > altogether? Well, IMO the naming should have been the other way around from the start. That is, we should have made pm_runtime_get be the synchronous routine and pm_runtime_get_async be the asynchronous one. But it's too late to change now. And no, we can't get rid of the async version. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
