Run OFW heat spreader test

James Cameron quozl at
Mon Jan 23 01:20:08 EST 2012

On Mon, Jan 23, 2012 at 05:03:29PM +1100, Sridhar Dhanapalan wrote:
> On 23 January 2012 16:56, James Cameron <quozl at> wrote:
> > The heat spreader test is always run in e-book mode, because that's what
> > the immediately preceeding test does.
> >
> > I imagine you would get different results if you didn't run it in e-book
> > mode. ?I imagine that over a large sample, the results would be
> > considerably different.
> For the purposes of flashing the XOs, does it matter?

We haven't measured how many units pass the test upright versus pass the
test in e-book mode, we only test in e-book mode.  If you think it
matters, you will have to characterise the result.

The manual handling of the upper section can also change the test result
when a heat spreader is in a marginal condition.  I have results that
show this.

I thought you were doing this test to detect early units that may have
a failed heat spreader, and you were doing it at the time of reflashing
because that's when you had some control.

I don't think it is worth doing this test for the purposes of flashing
the XOs.  The built in throttling will work fine.  If the heat spreader
is dodgy, you'll either get a hang during fs-update or it will take much

Of course, make sure the units are not racked, stacked, or placed under
a towel.

> > For the user training issue, stop using the manufacturing test prompts,
> > and replace them with something localised.
> >
> > dev /switches
> > : new-wait-lid ?( -- )
> > ?." Thermal test step 1, close and then re-open the laptop lid." cr
> > ? ? begin ??key-abort ?lid? until
> > ;
> > : new-wait-ebook ?( -- )
> > ?." Thermal test step 2, rotate the top part and lay it down face up."
> > cr
> > ?begin ??key-abort ?ebook? until
> > ?." Thermal test step 3, please wait a few seconds." cr
> > ;
> > patch new-wait-lid wait-lid all-switch-states
> > patch new-wait-ebook wait-ebook all-switch-states
> The problem is that this is very tedious for the user. Imagine you're
> flashing 100 XOs together. Having to close and open the lid twice per
> XO will make the entire process much longer.

Yes, as you can see above it really wasn't clear to me why you were
running the test.

Looking at your original post on the thread, I don't think heat
spreaders will be burnt-out by the flashing process.

James Cameron

More information about the Devel mailing list