"Page Fault" message on XO-1 and another Fix Clock question

[Christoph Derndorfer]

Hey James,

On Mon, Feb 4, 2013 at 5:32 AM, James Cameron <quozl at laptop.org> wrote:

> On Mon, Feb 04, 2013 at 12:58:47AM +0200, Christoph Derndorfer wrote:
> > (1) on Friday while looking at one of the XO-1s which didn't show
> > anything on the display (even with a display which was known to
> > work) with the serial adapter I saw the attached output.
>
> Reviewed, thanks.


thanks a lot for the quick reply.


> > Looking at the wiki now and given the number of "invalid system
> > date" issues we saw on other machines I assume this is a case of the
> > "page fault" message situation described on
> > http://wiki.laptop.org/go/Fix_Clock# If_the_screen_does_not_turn_on.
>
> Yes, this is likely.
>

Turns out this was indeed the issue and I now fixed it.


> > Or are there any other issues which could produce such an output?
>
> There might be, but if you have a version before Q2D05 which was
> released in 2007, there's almost no chance of anybody remembering
> anything useful.  It has been more than five years!
>
> To verify that the Page Fault is happening because of the known
> problem (ticket #5391, svn 752), please use the Open Firmware ok
> prompt to display the values in the real-time clock, using the .clock
> command:
>
>         ok .clock
>
> If the month is invalid, then the Page Fault is most likely to be the
> one expected.
>
> Another method would be to take an XO-1 with Q2D06 or earlier, remove
> the clock battery, force the problem again, and see if the serial log
> looks the same.  I expect it will.
>
> There are other methods to diagnose, but these require immediate
> collaboration with a firmware engineer, and I don't think it is worth
> doing that yet.
>
> > (2) Mike sent me a bunch of ML 1220 batteries as replacements for
> > the XO-1 units which showed the "invalid system date"
> > messages. However even with the new batteries in-place, after
> > verifying that the (old) battery holders looked okay and having set
> > the current time on the command-line the system date reverted back
> > to 2000-01-01 00:00:00 after every reboot (and hence the "invalid
> > system date" message kept coming up again). Any suggestions on what
> > to do in such a situation?
>
> Charge the battery before the power cycle test.  On the XO-1, "it will
> recharge from the main power source while the laptop is powered on and
> fully awake (not suspended)."
>
> "When recharging an empty battery, it is expected that the battery
> will reach normal voltage levels after around 30 minutes of charging,
> but will require potentially 24 hours for a complete recharge."
>
> http://wiki.laptop.org/go/Fix_Clock#RTC_power_dynamic has the above
> text.
>

Thanks a lot for that information, I had somehow managed to miss it.

I'm now charging the four XO-1s which are here in the office and still
displaying the "invalid system date" error. Let's see whether it works out.


> Check that the battery voltage is reasonable.
>
> Check that the connector is passing the voltage properly to the
> circuit board.
>

Unfortunately I don't have any measuring equipment here so I can't do that.


> Also, please make sure you upgrade the firmware as soon as you can, so
> that you aren't impacted by this problem any further.


All of the concerned XO-1s which have this problem are running firmware
Q2F12 (and 12.1.0).

Cheers,
Christoph

-- 
Christoph Derndorfer

volunteer, OLPC (Austria) [www.olpc.at]
editor, OLPC News [www.olpcnews.com]
contributor, TechnikBasteln [www.technikbasteln.net]

e-mail: christoph at derndorfer.eu
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