On Thu, 6 Mar 2008, Rafael J. Wysocki wrote: > On Thursday, 6 of March 2008, Alan Stern wrote: > > On Thu, 6 Mar 2008, Rafael J. Wysocki wrote: > > > > > > I thought of one more thing you might want to add: device_pm_add() > > > > doesn't handle the case where dev->parent is NULL. > > > > > > I'm not sure what you mean. > > > > > > If dev->parent is NULL, we get into the "successful" branch where the device is > > > added to dpm_active. Do you think we should add any extra handling of this > > > case? > > > > If a device is registered after dpm_suspend() has returned, the > > device won't be suspended properly before the system goes to sleep. > > > > If the device has a parent then you're okay, because the parent must > > already be suspended and so device_pm_add() will fail. But if the > > device doesn't have a parent then device_pm_add() will succeed, which > > you don't want. > > Well, can it happen in practice? If it can, then what way can it happen? Yes, it can happen in practice when a new module is loaded. In some ways, modules' init routines are like probe methods. Maybe it can happen some other ways too, but I don't know of any. > It seems to me that we're discussing purely academic stuff here. If it turns > out to be of any practical relevance, it will be trivial to add the handling of > it in the future. To be safe, I think we should make system sleep mutually exclusive with module loading. Alan Stern _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
