Re: [PATCH 07/13] ARM: dts: r8a7792: initial SoC device tree

Simon Horman
2016-06-16T00:06:49Z

On Wed, Jun 15, 2016 at 12:08:21AM +0300, Sergei Shtylyov wrote:
> Hello.
>
> On 06/14/2016 03:43 AM, Simon Horman wrote:
>
> >>>>[...]
> >>>>
> >>>>>>>And that the system behaves sanely on suspend/resume.
> >>>>>>
> >>>>>> I'd be thankful if you told me how to test that. :-)
> >>>>>
> >>>>>System suspend:
> >>>>>
> >>>>> echo mem > /sys/power/state
> >>>>
> >>>> Oh. I know that one! :-)
> >>>>
> >>>>>System resume: You're gonna need a "wakeup-source" in your DTS, e.g. gpio-keys.
> >>>>>Serial should work too, echo "enabled" to the corresponding wakeup
> >>>>>file in /sys first.
> >>>>
> >>>> I'm afraid I couldn't find that file. All I saw were RPM controls...
> >>>>
> >>>>>In case of issues, try "echo 0 > /sys/module/printk/parameters/console_suspend".
> >>>>
> >>>> There's no problems suspending, it's the resuming that's a problem for me.
> >>>>
> >>>>>Good luck!
> >>>>
> >>>> As usual, there was no luck. :-)
> >>>>
> >>>>WBR, Sergei
> >>>
> >>>Does resume work for UP (i.e. without SMP)?
> >>
> >> No. My problem with resume is I can't wake up the remote system. I don't
> >>see the needed 'wakeup' file in
> >>/sys/devices/platform/soc/e6e60000.serial/...
> >> However, if I enable CONFIG_PM_[ADVANCED_]DEBUG and do
> >>
> >>$ echo -n core /sys/.power/pm_test
> >>
> >>the system happily wakes up after a small delay (5 s), w/either SMP or UP kernel.
> >
> >That seems promising but it seems curious that there is no wakeup file.
> >
> >On Lager the following procedure works for me using
> >renesas-devel-20160613-v4.7-rc3 and shmobile defconfig.
> >
> >0. Add wakeup-source property to serial@e6ce0000 node in DT
>
> Ah, stupid me, it was the piece that I'd overlooked!
>
> >1. echo enabled > /sys/devices/platform/e6e60000.serial/tty/ttySC0/power/wakeup
> >2. echo mem > /sys/power/state
> >3. Provide input on serial console
> >
> >* Success! *
>
> Yeah, works now!
> Sorry, I had no previous experience with the PM. Was unsupported feature
> back in MontaVista... :-)

Great, thanks for your persistence.

FWIW, I always have to refer to some notes in order to exercise PM.

> >>>How did testing CPU hotplug go? Did it work for all CPUs?
> >>
> >> Sure!
> >
> >Great!
> >
> >> The only problem I'm seeing (again) is the RCAN clock failing to register:
> >>
> >>rcar_gen2_cpg_clocks_init: failed to register cpg_clocks rcan clock (-12)
> >>
> >> I was going to look at it yesterday but (wrongly) thought it somehow
> >>cured itself... I'll look at it now.
> >
> >Is this resolved? If not perhaps you could consider removing the node
> >in question for now.
>
> That's what I did in v5, i.e. removed the RCAN CPG clock (not the whole
> node)...

Great.