Re: HDD problem, software bug, bios bug, or hardware ?

Mikael writes:

Please try the patch below, which implements the fix I described a
week ago. It's for 3.6-rc4 but should work in any recent kernel.
Without this patch one of my test machines always throws a lockdep
warning involving pdc_sata_hardreset and pdc_interrupt during bootup,
but with the patch the warning is gone, as expected.

If it works for you I'll add your Tested-by: and submit it properly.

Your patch seems to work, as the warning message is gone after applying it, i tried it with linux-3.5.2,
 and post here links to dmesg before and after applying the patch:

before: http://pastebin.com/Y80AYYVK

after:    http://pastebin.com/Am0Zuabz



Borislav writes:

Hmm, Cool'n'Quiet enabled actually means that you have _PSS objects and
powernow-k8 should be detecting the P-states properly.

Can you catch dmesg from that machine twice?

* one with Cool'n'Quiet disabled
* one with the kernel panic

I hope i will be able to do it some time in the future, because i have no any physical contact with this machine,
moreover it will require photo of the monitor after panic message, as it happens at boot process - fs not mounted yet,
network not set, so i can not catch a message with netconsole.


Borislav writes:

Right, so AFAICU, you can run a CONFIG_PREEMPT kernel perfectly fine now
after the BIOS update, right?

Right.


Borislav writes:

If so and when you say that the oopses started happening after an
electrical instability, I'd venture a guess that something got damaged
in the BIOS EPROM and since you've flashed it anew, the corrupted data
got overwritten and so no more crashes. Correct?

The thought crossed my mind, but i still can not imagine how could it happens.
Even if bios keeps some of the settings into EPROM, instead of CMOS, 
it should flash itself just after changing the settings, which is not the case, if i was right informed.
There may be some other way that electricity break could damage EPROM content, somehow more directly,
beyond the mechanisms by design, i don't know.
Anyway, for the known facts we have, this explanation sounds pretty satisfactory, as long as no more crashes appears :).


Thanks !

Regards
Adko.