"Rafael J. Wysocki" <rjw@xxxxxxx> writes: > On Tuesday 04 May 2010, Mark Brown wrote: >> On Tue, May 04, 2010 at 11:06:39AM -0700, Kevin Hilman wrote: >> >> > With opportunistic suspend, all of this flexibility is gone, and the >> > device/subsystem is told to go into the lowest power, highest latency >> > state, period. >> >> Well, half the problem I have is that unfortunately it's not a case of >> doing that period. The prime example I'm familiar with is that for >> understandable reasons users become irate when you power down the audio >> CODEC while they're in the middle of a call so if opportunistic PM is in >> use then the audio subsystem needs some additional help interpreting a >> suspend request so that it can figure out how to handle it. Similar >> issues apply to PMICs, though less pressingly for various reasons. >> >> Just to be clear, I do understand and mostly agree with the idea that >> opportunistic suspend presents a reasonable workaround for our current >> inability to deliver good power savings with runtime PM methods on many >> important platforms but I do think that if we're going to make this >> standard Linux PM functionality then we need to be clearer about how >> everything is intended to hang together. > > At the moment the rule of thumb is: if you don't need the opportunistic > suspend, don't use it. It is not going to be enabled by default on anything > other than Android right now. Sure, but there are driver authors and subsystem maintainers who care about optimal PM in "normal" Linux *and* in Android. As a PM maintainer for an embedded platform (OMAP) used in both, I certainly care about both, so "disable it if you don't like it" is not really an option. IMO, driver/subsystem authors should not have to care if the userspace is Android or not. We should be working towards a world where Android is not a special case. Kevin _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
