Re: Suspend/Resume Broken on AM43/AM33 Platforms

From: Stephen Boyd
Date: Mon Aug 19 2019 - 11:00:28 EST


Quoting Keerthy (2019-08-19 00:27:13)
>
>
> On 19/08/19 11:57 AM, Stephen Boyd wrote:
> > Quoting Keerthy (2019-08-18 21:24:58)
> >> Hi Stephen,
> >>
> >> commit 03a3bb7ae63150230c5de645dc95e673ebf17e1a
> >> Author: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> >> Date: Mon Aug 5 16:32:41 2019 -0700
> >>
> >> hwrng: core - Freeze khwrng thread during suspend
> >>
> >> Commit seems to be breaking suspend/resume on TI AM43/AM33 platforms.
> >>
> >>
> >> rtcwake: wakeup from "mem" using /dev/rtc0 at Sun Nov 18 02:12:12 2018
> >> [ 54.033833] PM: suspend entry (deep)
> >> [ 54.037741] Filesystems sync: 0.000 seconds
> >> [ 54.062730] Freezing user space processes ... (elapsed 0.001 seconds)
> >> done.
> >> [ 54.071313] OOM killer disabled.
> >> [ 54.074572] Freezing remaining freezable tasks ...
> >> [ 74.083121] Freezing of tasks failed after 20.003 seconds (1 tasks
> >> refusing to freeze, wq_busy=0):
> >> [ 74.092257] hwrng R running task 0 289 2
> >> 0x00000020
> >> [ 74.099511] [<c08c64c4>] (__schedule) from [<c08c6a10>]
> >> (schedule+0x3c/0xc0)
> >> [ 74.106720] [<c08c6a10>] (schedule) from [<c05dbd8c>]
> >> (add_hwgenerator_randomness+0xb0/0x100)
> >> [ 74.115358] [<c05dbd8c>] (add_hwgenerator_randomness) from
> >> [<bf1803c8>] (hwrng_fillfn+0xc0/0x14c [rng_core])
> >
> > Thanks for the report. I suspect we need to check for freezer in
> > add_hwgenerator_randomness(). I find it odd that there's another caller
> > of add_hwgenerator_randomness(), but maybe the ath9k driver can be
> > converted to some sort of hwrng driver instead of calling into the
> > kthread directly.
> >
> > Anyway, can you try this patch?
>
> I applied the below patch on top of latest next branch.
>
> Fixes the issue.
>

Cool thanks. I'll send an official patch now.