Last old PowerMac G5 that I have access to may be starting to fail: iichb0: I2C error

[Mark Millard]

On 2021-Apr-16, at 13:41, Brandon Bergren <bdragon at FreeBSD.org> wrote:

> Do you have a dmesg? There's some bits in the thermal drivers I've been looking into recently where I have certain machines where the thermal chip is left in automatic mode but also the system attempts to drive it in manual mode, which causes things like the fans jerking on and off and spurious 103.0C readings on the temperature probe the chip is internally sampling. I half wonder if there's a similar issue causing us to accidentally crash the chip or something.

I'm unclear on what you are after. The only time it left
any evidence behind was the one line that I reported.
(It was on the console --and in /var/logs/messages after
power off/power on.) I've never gotten more information
from it left powered on, not even via FireWire dcons:
no response to the outside world until after power-off
then power-on.

But if you are after some part of a "dmesg -a" output or
some such during normal operation, no failure, I can
extract information and provide it. Or even verbose boot
information if you want.

I've not been seeing messages about temperatures,
including in /var/log/messages , or hearing odd fan
activity during its normal operation.

For reference, it is running based on 7381bbee29df from
back on 2021-03-12, but, as usual for me, it is running
with my workaround patches for PowerMacs as well:

# ~/fbsd-based-on-what-freebsd-main.sh 
FreeBSD FBSDG5L2 14.0-CURRENT FreeBSD 14.0-CURRENT mm-src-n245445-def0058cc690 GENERIC64vtsc-NODBG-dcons  powerpc powerpc64 1400005 1400005
def0058cc690 (HEAD -> mm-src) mm-src snapshot for mm's patched build in git context.
merge-base: 7381bbee29df959e88ec59866cf2878263e7f3b2
merge-base: CommitDate: 2021-03-12 20:29:42 +0000
7381bbee29df (freebsd/main, freebsd/HEAD, pure-src, main) cam: Run all XPT_ASYNC ccbs in a dedicated thread
n245444 (--first-parent --count for merge-base)


> On Thu, Apr 15, 2021, at 10:53 PM, Mark Millard via freebsd-ppc wrote:
>> The 2-socket/1-core-each PowerMac G5 has had several
>> sudden crashes recently, mostly while idle, usually
>> with no messages. No response but to power controls
>> once it fails.
>> 
>> But I got one example (so far) where it reported
>> something as it failed (and the fans then started
>> to speed up):
>> 
>> iichb0: I2C error
>> 
>> The message was even recorded in /var/log/messages .
>> 
>> The kernel and world have not been updated since
>> back around 2021-Mar-12 or so. So the behavior
>> appears to be new, without a system software change
>> in a similar time frame.
> 


===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)