panic: device_unbusy: called for non-busy device iichid0

From: David Wolfskill <david_at_catwhisker.org>
Date: Thu, 27 May 2021 04:41:45 -0700
This was on the new(er) laptop with which I have been experimenting; it
uses iichid to controll/access the built-in mouse/touchpad.

The machine was running:

FreeBSD g1-48.catwhisker.org 14.0-CURRENT FreeBSD 14.0-CURRENT #252 main-n246951-38e7025a60b2: Wed May 26 04:56:25 PDT 2021     root_at_g1-48.catwhisker.org:/common/S4/obj/usr/src/amd64.amd64/sys/CANARY  amd64 1400017 1400017

at the time.  Note that the reboot after building the above (yesterday)
was without issue, and the reboot after the panic was also without issue
-- so this would seem to have elements of timing/racing involved.  (And
it's likely to be distinctly unpleasant to debug, as it seems that
reproduction may be rather "iffy.")

I took a photo of the displayed backtrace; it's at
https://www.catwhisker.org/~david/FreeBSD/head/n246951/device_unbusy.jpg

Here's a slightly-abbreviated hand-transcribed version:

panic: device_unbusy: called for non-busy device iichid0
cpuid = 8
time = 1622113818
KDB: stack backtrace:
db_trace_self_wrapper()
vpanic()
panic()
device_unbusy()
iicbus_release_bus()
iichid_intr()
ithread-loop()
fork_exit()
fork_trampoline()
--- trap 0, rip = 0, rsp = 0, rbp = 0 ---
KDB: enter: panic
[ thread pid 12 tid 100170 ]
Stopped at      0xffffffff80c36867 = kdb_enter+ 0x37:    $0,0x12a0b9e(%rip)
db> 


Peace,
david
-- 
David H. Wolfskill                              david_at_catwhisker.org
Republican Congressional leaders are giving support to those who took up
arms against the government of the United States on 06 January 2021.

See https://www.catwhisker.org/~david/publickey.gpg for my public key.

Received on Thu May 27 2021 - 11:41:45 UTC

Original text of this message