kern/53535: lockup with nouveau updating fans

[martin%NetBSD.org@localhost]

>Number:         53535
>Category:       kern
>Synopsis:       lockup with nouveau updating fans
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Aug 17 13:20:00 +0000 2018
>Originator:     Martin Husemann
>Release:        NetBSD 8.0_STABLE
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD emmas.aprisoft.de 8.0_STABLE NetBSD 8.0_STABLE (EMMAS) #0: Wed Aug 15 11:55:07 CEST 2018 martin%seven-days-to-the-wolves.aprisoft.de@localhost:/work/src-8/sys/arch/amd64/compile/EMMAS amd64
Architecture: x86_64
Machine: amd64
>Description:

This machine locked up - responsive to ddb but nothing else worked.
Breaking into ddb always ended up like this:

comintr() at netbsd:comintr+0x54b
Xhandle_ioapic_edge4() at netbsd:Xhandle_ioapic_edge4+0x66
--- interrupt ---
x86_pause() at netbsd:x86_pause+0x2
nouveau_fantog_update() at netbsd:nouveau_fantog_update+0x55
nouveau_fantog_set() at netbsd:nouveau_fantog_set+0x46
nouveau_fan_update() at netbsd:nouveau_fan_update+0xdd
nv04_timer_alarm_trigger() at netbsd:nv04_timer_alarm_trigger+0x126
nouveau_fantog_update() at netbsd:nouveau_fantog_update+0x192
nv04_timer_alarm_trigger() at netbsd:nv04_timer_alarm_trigger+0x126
nv04_timer_intr() at netbsd:nv04_timer_intr+0x67
nouveau_mc_intr() at netbsd:nouveau_mc_intr+0x130
intr_biglock_wrapper() at netbsd:intr_biglock_wrapper+0x36



>How-To-Repeat:
n/a

>Fix:
n/a