Best way to debug an Intel Core i5 hang - likely graphics (possibly power) related

Mulyadi Santosa mulyadi.santosa at gmail.com
Thu Jan 19 23:05:48 EST 2012


Hi Graeme :)

On Fri, Jan 20, 2012 at 09:20, Graeme Russ <graeme.russ at gmail.com> wrote:
> This may not be the best place to post this question, so please excuse...
>
> I have a brand new Intel i5 / z68 EUFI motherboard (ASRock Z68 Pro3
> Gen3) with 8GB RAM running Fedora 16 (64 bit) which is experiencing
> lockups which send the video crazy (flashing screen) but there is
> nothing appearing in /var/log/messages to indicate what is going wrong
> (no oops).
>
> I'm sure it is graphics related. I thought of Cc'ing the i915
> maintainer (Keith Packard) but figured I should wait until I am sure
>
> I _think_ it might be power related as the hang never seems to occur
> while I'm actively using the computer - Only after I have stopped for
> a few minutes does it happen but not always.

>From your description alone, I think it's still hard to pinpoint the
root of the problem. So I guess we'll gonna play cat and mouse a bit
here.

First of all, IMHO you still need to do logging. Maybe, just maybe,
the reason why you don't see anything suspicious in /var/log/messages
because the lock is bad enough that prevents the error messages to be
picked up. Try setting up netconsole (here is the clue:
https://wiki.ubuntu.com/Kernel/Netconsole) or serial console (try
reading http://linux.koolsolutions.com/2009/03/29/howto-redirecting-linux-console-output-over-serial-port-on-another-machine/).
Hopefully it will catch suspicious message.

You could also enable several verbose debugging message under "Kernel
hacking" section during "make menuconfig".

Hope it helps....

NB: You said if it actively used, it goes well? Sounds like dynamic
CPU frequency adjustment bug....

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com



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