Hi Ulf,
On Thu, Oct 27, 2016 at 1:53 PM, Ulf Hansson <[email protected]> wrote:
> On 27 October 2016 at 13:41, Geert Uytterhoeven <[email protected]> wrote:
>> On Thu, Oct 27, 2016 at 1:23 PM, Ulf Hansson <[email protected]> wrote:
>>> The smsc911c driver puts its device into low power state when entering
>>> system suspend. Although it doesn't update the device's runtime PM status
>>> to RPM_SUSPENDED, which causes problems for a parent device.
>>>
>>> In particular, when the runtime PM status of the parent is requested to be
>>> updated to RPM_SUSPENDED, the runtime PM core prevent this, because it's
>>> forbidden to runtime suspend a device, which has an active child.
>>>
>>> Fix this by updating the runtime PM status of the smsc911x device to
>>> RPM_SUSPENDED during system suspend. In system resume, let's reverse that
>>> action by runtime resuming the device and thus also the parent.
>>
>> Thanks for your patch!
>>
>> The changelog sounds quite innocent, but this does fix a system crash
>> during resume from s2ram.
>>
>>> Signed-off-by: Ulf Hansson <[email protected]>
>>> Tested-by: Geert Uytterhoeven <[email protected]>
>>> Cc: Steve Glendinning <[email protected]>
>>> Fixes: 8b1107b85efd ("PM / Runtime: Don't allow to suspend a device with an
>>> active child")
>>
>> While the abovementioned commit made the problem visible, the root cause
>> was present before, right?
>
> Yes.
>
>>> ---
>>>
>>> Note that the commit this change fixes is currently queued for 4.10 via
>>> Rafael's linux-pm tree. So this fix should go via that tree as well.
>>
>> Alternatively, this could go in in v4.9 to avoid the problem from ever
>> appearing in upstream?
>
> Makes perfect sense! In that case we should remove the fixes tag.
>
> Rafael, can you pick this up for 4.9 rc[n]?
Actually I was thinking about DaveM and the network tree instead.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
