Re: [PATCH v2 09/14] PM / Runtime: hold device active during device_wakeup_{enable|disable}

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On Fri, Nov 22, 2013 at 4:06 PM, Rafael J. Wysocki
<rafael.j.wysocki@xxxxxxxxx> wrote:
> On 11/22/2013 8:29 PM, Dan Williams wrote:
>>
>> On Fri, Nov 22, 2013 at 7:50 AM, Rafael J. Wysocki
>> <rafael.j.wysocki@xxxxxxxxx> wrote:
>>>
>>> On 11/22/2013 10:08 AM, Dan Williams wrote:
>>>>
>>>> usbcore blocks powering off hub ports while a downstream source is
>>>> wakeup enabled.  Once wakeup is disabled usbcore can try again to turn
>>>> off the parent port.  Add a pm_runtime reference manipulation to retry a
>>>> port power down on disable, or pin the port active on enable.
>>>>
>>>> Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>>>> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
>>>
>>>
>>> Well, while this generally won't hurt, I'm not sure how it helps either,
>>> because device_(disable|enable)_wakeup() don't touch any hardware and
>>> (for
>>> now) they are only about wakeup from system suspend.
>>>
>> If a USB device's parent port is turned off prior to system suspend
>> then remote wakeup will be blocked.
>
>
> Do you mean it won't wake up from system suspend?  Or something else?
>

The former, remote wakeup from system suspend will fail if the parent
port is disabled.

>
>> We could handle this internally
>> by correcting the setting at suspend time, but would need to wake the
>> port and possibly recover the connection to suspend.  Just seemed
>> cleaner to notify the setting change.
>
>
> I'm not sure I understand you correctly.
>
> So you want your .runtime_resume() callback to be executed when the system
> wakeup setting is changed so that you know that it has been changed?  Or do
> you mean something different?
>

Correct, want this device and its parent port to notice the change.
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