* Johan Hovold <johan@xxxxxxxxxx> [161021 02:26]:
> On Fri, Oct 21, 2016 at 12:08:49AM -0700, Tony Lindgren wrote:
> > * Johan Hovold <johan@xxxxxxxxxx> [161020 08:38]:
> > > Hi Tony,
> > >
> > > I'm getting the splat below when booting 4.9-rc1 on a BBB and
> > > tracked it down to 65b3f50ed6fa ("usb: musb: Add PM runtime support for
> > > MUSB DSPS glue layer") which added a synchronous RPM get in a timer
> > > callback:
> >
> > OK, sorry to hear about that. Care to email me your .config and how
> > to reproduce and what do you have connected like a hub? Also do
> > you use built-in gadgets or configure them via configfs?
>
> It happens even with no devices connected to the host port, and with no
> gadgets configured (or the peripheral port simply disabled). Whenever
> the glue timer fires and calls pm_runtime_get_sync() I get the splat.
> For some reason the might_sleep() in get_sync() does not trigger the
> first time, which means that I see this four seconds after probe, and
> then every other second when the timer fires.
OK. I'm totally baffled how come I did not hit this earlier with
my tests. I did have some extra patches for using the pmic vbus irq
for cable detection, but that's only for the peripheral instance and
the host instance is still using timer.
> Attaching my defconfig.
Not seeing anything special there, musb built in, using dma. And no
reason why this should not always happen when polling the cable status.
> > > Setting the irq_safe flag seems to do the trick, but not sure that's
> > > what you intended to do.
> >
> > That's what we want to avoid as it keep the parent device permanently
> > enabled. To avoid that we want to just queue things and deal with them
> > from pm_runtime_resume.
>
> I figured, so then that pm_runtime_get_sync() in the dsps timer callback
> needs to go.
Agreed, that is clearly wrong to call from softirq context. I need to
figure out what is right fix here but don't have access to my bbb
until next week.
> > > I saw you posted some regression fixes lately, but they did not look
> > > related to this at first glance at least.
> >
> > Yeah this seems different. Can you still try v4.9-rc + patches from
> > thread "[PATCH 0/2] Fixes for two more musb regressions"?
>
> As expected, those two fixes makes no difference.
Yeah thanks for checking.
Regards,
Tony
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