Re: PM: after suspend/resume the system,can not suspends again

[Ulf Hansson]

On 16 November 2015 at 10:13, Cao Minh Hiep <cm-hiep@xxxxxxxxxxx> wrote:
> Dear Ulf Hansson,
>
> I am Hiep from Jinzai Solution (a Japanese Company)
> We have tested PM driver on Rcar-Gen2 (Lager, Koelsch Board) at Linux v4.3.
>
> I would like to contact you because we found a patch that relate to a PM bug
> :
>
> After Suspend/resume system one time, we can not suspend the system again!.
> (I attach the test log file)
>
> The patch is show as below:
> a98f1b7 PM / Domains: Fix validation of latency constraints in genpd
> governor
>
> Tested-by: Harunaga <nx-truong@xxxxxxxxxxx>
> Reported-by: Cao Minh Hiep <cm-hiep@xxxxxxxxxxx>
>
> This problem disapeared if revert this patch.
> Please review it, when you have time!

Thanks for reporting and bisecting!

I had a look and I believe have found the cause of the problem, though
I will need a few days to post a fix for it.

The problem is actually in genpd's ->runtime_suspend() callback, as it
validates PM QoS latencies even when it's being invoked from the
system PM path.
I will post a fixup to genpd in the next couple of days. I would
appreciate if you could help out in testing it.

Kind regards
Uffe
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