[ltp] 770X Error codes?

[Bjorn Knutsson]

Fabrice Bellet wrote:
> On Sat, Jul 15, 2000 at 09:08:43PM +0200, Bill Mair wrote:
> > Fabrice Bellet wrote:
> > 
> > When did you do this ?
> > And when were you aware of this problem ?
> > Why didn't you warn us here on the list that playing around with the I2C
> > lm_sensors stuff breaks ThinkPads ?
> > 
> > I'm now I'm really worried about the 2.4 kernel, if any distribution
> > enables
> > this stuff by default and probes the I2C bus looking for lm_sensors
> > support
> > will this then break my ThinkPad ???
> > 
> > Oh god, life is about to get very complicated installing V2.4.x kernel
> > based
> > distributions...
> 
[Stuff deleted]
> I suggested to the lm_sensors maintainer, that there could be
> a problem with the eeprom module. He told me that two things could
> have happened :
>     1 : the SMBus got locked in a state that makes it impossible
>         to read from it. the motherboard serial numbers are
> 	unaccessible. 
> 	A cold reboot could help : removing all power supply, waiting
> 	a few minutes and reinserting them.
>     2 : EEPROM data got mangled. The maintainer thinks this is very
>         unlikely, because the eeprom module in lm_sensors
> 	has no write capability (a the time of writing, ie January).
> 
> The first case didn't really fit with what I experienced, because
> removing power supply did not help me. But there may be another
> sort of internal battery the PIIX4 bus may be connected on...

I can't tell which, but I can relate my own tale of woe.

My machine, a 600X, refused to boot with the very same errors about a month
after I got it, and now that I think about it, I did play around with
lm_sensors prior to the reboot after which this problem manifested itself.

I never got lm_sensors to give me any interesting info, so I removed them
before rebooting. I guess this is why I never had the problem more than this
one time.

I'd advise all Thinkpad owners to stay clear of lm_sensors. Also, I question
the wisdom of building a machine that can be totally and unrecoverably disabled
by software. I'm all for software upgradeable BIOSes and stuff, but there must
be a ROM in there somewhere; why not put a small bootstrap in it that allows
the user to rewrite thrashed EEPROMs from, say, a floppy?

/Björn
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