Re: [PATCH v2 00/18] i.MX8MM GPC improvements and BLK_CTRL driver

[Lucas Stach <l.stach@pengutronix.de>]

Hi Frieder,

Am Mittwoch, dem 01.09.2021 um 12:03 +0200 schrieb Frieder Schrempf:
[...]
> > > 
> > > > 
> > > > And I would appreciate if someone else could try to reproduce this problem on his/her side. I use this simple script for testing:
> > > > 
> > > > #!/bin/sh
> > > > 
> > > > glmark2-es2-drm &
> > > > 
> > > > while true;
> > > > do
> > > >     echo +10 > /sys/class/rtc/rtc0/wakealarm
> > > >     echo mem > /sys/power/state
> > > >     sleep 5
> > > > done;
> > > 
> > > Hm, that's unfortunate.
> > > 
> > > I'm back from a two week vacation, but it looks like I won't have much
> > > time available to look into this issue soon. It would be very helpful
> > > if you could try to pinpoint the hang a bit more.  If you can reproduce
> > > the hang with no_console_suspend you might be able to extract a bit
> > > more info in which stage the hang happens (suspend, resume, TF-A, etc.)
> > > If the hang is in the kernel you might be able to add some prints to
> > > the suspend/resume paths to be able to track down the exact point of
> > > the hang.
> > > 
> > > I'm happy to look into the issue once it's better known where to look,
> > > but I fear that I won't have time to do the above investigation myself
> > > short term. Frieder, is this something you could help with over the
> > > next few days?
> > 
> > I will see if I can find some time to track down the issue at least a little bit more. But I imagine it could get quite tedious if it takes up to several hours to reproduce the issue and I don't have much time to spare.
> > 
> > @Peng, @Adam and everyone else: Any chance you could setup a similar test and try to reproduce this?
> > 
> > On the other hand reboot cycle testing didn't show any lockup problems over more than 24 hours, so it seems like the issue is limited to resume.
> 
> I ran a few more suspend/resume cycles and watched the log. The first
> 2.5 hours nothing noteworthy happened, except that glmark2 crashed again
> at some point.
> 
> Then suddenly the following lines were printed while suspending:
> 
>   imx-pgc imx-pgc-domain.6: failed to command PGC
>   PM: dpm_run_callback(): platform_pm_suspend+0x0/0x78 returns -110
>   imx8m-blk-ctrl 38330000.blk-ctrl: PM: failed to suspend: error -110
>   PM: Some devices failed to suspend, or early wake event detected
> 
> After that, the suspending continues to fail with the following on each try:
> 
>   PM: dpm_run_callback(): platform_pm_suspend+0x0/0x78 returns -22
>   imx8m-blk-ctrl 38330000.blk-ctrl: PM: failed to suspend: error -22
>   PM: Some devices failed to suspend, or early wake event detected
> 
> So far I didn't run into a lockup again with this test, but I will
> continue trying to reproduce it and retrieve more information.

If you run into this "failed to command PGC" state again, I would be
very interested in the GPC state there. You should be able to dump the
full register state from the GPC regmap in debugfs.

Regards,
Lucas