On Fri, Oct 14, 2011 at 12:04 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Thu, 13 Oct 2011, Ming Lei wrote: > >> Hi, >> >> On Thu, Oct 13, 2011 at 10:31 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> >> >> Maybe we should understand the correct model of the ordering constraints >> >> for the multiple device dependancies first, could you give a description or >> >> some examples about it? >> > >> > The requirement is that devices must be capable of resuming in the >> > order given by dpm_list, and they must be capable of suspending in >> > the reverse order. >> > >> > Therefore if device A can't work unless device B is functional, then B >> > must come before A in dpm_list. >> >> If all devices can support async suspend and resume correctly, looks like >> the device order given by dpm_list is not needed any longer, doesn't it? > > It _is_ needed, because the user can disable async suspend/resume via > /sys/power/pm_async. > > Also, not all devices do support async suspend/resume. Basically, the devices which don't support async suspend/resume should have out of tree PM dependency. If out of tree PM dependency issue is solved, all devices can support async suspend/resume. thanks, -- Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
