On Tue, 20 Oct 2015, Tomeu Vizoso wrote: > On 20 October 2015 at 18:04, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > On Tue, 20 Oct 2015, Mark Brown wrote: > > > >> On Tue, Oct 20, 2015 at 10:40:03AM -0400, Alan Stern wrote: > >> > >> > Furthermore, that applies only to devices that use synchronous suspend. > >> > Async suspend is becoming common, and there the only restrictions are > >> > parent-child relations plus whatever explicit requirements that drivers > >> > impose by calling device_pm_wait_for_dev(). > >> > >> Hrm, this is the first I'd noticed that feature though I see the initial > >> commit dates from January. > > > > Async suspend and device_pm_wait_for_dev() were added in January 2010, > > not 2015! > > > >> It looks like most of the users are PCs at > >> the minute but we should be using it more widely for embedded things, > >> there's definitely some cases I'm aware of where it will allow us to > >> remove some open coding. > >> > >> It does seem like we want to be feeding dependency information we > >> discover for probing way into the suspend dependencies... > > > > Rafael has been thinking about a way to do this systematically. > > Nothing concrete has emerged yet. > > This iteration of the series would make this quite easy, as > dependencies are calculated before probes are attempted: > > https://lkml.org/lkml/2015/6/17/311 But what Rafael is proposing is quite general; it would apply to _all_ dependencies as opposed to just those present in DT drivers or those affecting platform_devices. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
