Re: Powerbook shuts down hard when hot, patch found

[Michael Buesch <mb@bu3sch.de>]

On Saturday 29 September 2007 01:04:13 Benjamin Herrenschmidt wrote:
> 
> On Fri, 2007-09-28 at 23:32 +0200, Michael Buesch wrote:
> > Hi,
> > 
> > some time ago I already mailed you about this problem.
> > I will quickly describe what's going on, again:
> > 
> > My powerbook boots fine when it's cold. You can work with
> > it and you can also run it hot (compile something, etc...).
> > But when you try to boot it while it is hot, it will
> > automatically shutdown hard inside of the boot process.
> > Some part of the hardware is shutting it down.
> > This does not happen when it's getting hot _after_ boot.
> > Only while boot when it's hot.
> > 
> > I bisected the problem and found out that the following patch
> > is responsible for this. Yeah, this sounds a little bit
> > crazy, as this patch does not seem to be related to
> > this at all. But I confirmed it by booting kernel
> > 4f71c5de19c27f2198105d3b26b398494d5c353b
> > That kernel triggered the bug. Then I patch -R the patch below
> > and it booted properly, even when hot. I also rechecked
> > that it really was hot enough to trigger the event by
> > immediately rebooting into a known bad kernel, that immediately
> > shut down the pbook, as expected.
> > So I'm pretty sure it's the patch below causing this weird
> > behaviour. Any idea why?
> 
> This is very strange... Can you try also clearing VGA_DDC_CLK_OUT_EN and
> VGA_DDC_DATA_OUT_EN and the same time and see if that helps ?

It still triggers the bug then.

-- 
Greetings Michael.