Suspend/Resume Broken on AM43/AM33 Platforms

From: Keerthy
Date: Mon Aug 19 2019 - 00:24:40 EST


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])
[ 74.125356] [<bf1803c8>] (hwrng_fillfn [rng_core]) from [<c015abec>] (kthread+0x134/0x148)
[ 74.133764] [<c015abec>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
[ 74.141093] Exception stack(0xec611fb0 to 0xec611ff8)
[ 74.146239] 1fa0: 00000000 00000000 00000000 00000000
[ 74.154478] 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 74.162764] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[ 74.169499] Restarting kernel threads ... done.
[ 74.175628] OOM killer enabled.
[ 74.178796] Restarting tasks ... done.
[ 74.226769] PM: suspend exit
rtcwake: write error
1

One task refusing to freeze is the final error i am seeing.

- Keerthy