Messages in this thread | | | Date | Thu, 6 Mar 2008 12:40:37 -0500 (EST) | From | Alan Stern <> | Subject | Re: [RFC][PATCH] PM: Make PM core handle device registrations concurrent with suspend/hibernation |
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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.
> > You could put in that static "all_devices_sleeping" flag, which gets set at > > the end of dpm_suspend() and cleared at the start of dpm_resume(). > > Well, I don't think it's necessary. dpm_active is empty in that case and > we can use the list_empty(&dpm_active) check instead.
What would happen the very first time the system registers a device during startup?
Alan Stern
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