Comment 538 for bug 1690085

With Ryzen 1600X + Radeon RX 550 + ASRock Taichi X370 I didn't have this bug until 4.18.20. 4.18.18 had 12 days uptime and 4.18.20
(and 4.19.6) maybe 6 hours. 4.18.19 now has 56 hours uptime.

X just freezes (keyboard+mouse dead) and I have to press reset button. Likewise, if I am in console, freeze happens the same way; cursor stops blinking and I don't get any messages.

I am booting with nosmt=force rcu_nocbs=0-5 mem_encrypt=off
 (also CONFIG_RCU_NOCB_CPU=Y ).

Now, I don't feel like doing git-bisect (commits v4.18.19..v4.18.20),...
Does someone have ideas as to what to try next? Anything suspicious in v4.18.20 commits?

Some differences in dmesg 4.18.19..4.18.20:

-smpboot: Allowing 16 CPUs, 10 hotplug CPUs
+smpboot: Allowing 16 CPUs, 4 hotplug CPUs
-.... node #0, CPUs: #1 #2 #3 #4 #5
+.... node #0, CPUs: #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11
 smp: Brought up 1 node, 6 CPUs
 smpboot: Max logical packages: 3

-ACPI: (supports S0 S5)
+ACPI: (supports S0 S3 S5)