On Sunday 01 March 2009, Arve Hjønnevåg wrote: > On Sat, Feb 28, 2009 at 2:53 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote: > > On Saturday 28 February 2009, Arve Hjønnevåg wrote: > >> Can you summarize what the problems with my current api are? I get the > >> impression that you think the overhead of using a list is too high, > >> and that timeout support should be removed because you think all > >> drivers that use it are broken. > > > > In no particular order: > > 1. One user space process can create an unlimited number of wakelocks. This > > shouldn't be possible. Moreover, it is not even necessary for any process > > to have more than one wakelock held at any time. > > This has been addressed. A user space process cannot create more > wakelocks than it has filedescriptors. > > > 2. Timeouts are wrong, because they don't really _solve_ any problem. They are > > useful for working around the fact that you can't or you don't want to > > modify every piece of code that in principle should take a wakelock and > > that's it. > > Yes, timeouts are sometimes wrong, but they are not always wrong. I > gave two examples where the use of timeouts was not incorrect. There still is a problem that the same operation can take time X on one platform and time Y on another, so how are you going to determine the timeouts that will be suitable for all platforms? > > However, entire concept of having one code path acting on > > behalf of another one on a hunch that it might be doing something making > > suspend undesirable is conceptually broken IMO. > > OK. Do you have an alternative? Well, IMO every code path doing something that makes automatic suspend undesirable should use a suspend blocker of some sort. I'm afraid any other approach will be unreliable and racy. > I my opinion this is how the entire system works if you do autosuspend > without a mechanism like wakelocks. It surely hasn't been designed with automatic suspend in mind. Thanks, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
