TiBook shutoff during file transfer

[Jeffrey Baker]

On Wed, May 29, 2002 at 02:14:57PM -0400, William K. Gibson wrote:
> on 5/29/02 11:17 AM, Jeffrey Baker at jwbaker@acm.org wrote:
> 
> > BenH explained to me that the power management unit has to be
> > serviced periodically
> 
> Do you mean literally serviced by Apple? How the heck is that to be done-
> call them up and send it in?

No of course not.  I mean that the software has to deal with the PMU
from time to time.  If this does not happen, the PMU is designed to
shut the machine down.

It's probably as simple as the software telling the PMU, via some
register, that the operating system is still running.

I now remember that the last culprit to trigger this problem was
firewire.  According to Ben on the linux1394-devel mailing list:

"I didn't yet try to isolate what exactly is going on wrong as if
things are not done exactly the correct way, the machine likes to
shut down abruptly and lost some firmware settings & real time clock
(that's a nice "feature" of the power manager chip of powerbooks
when it times out, a machine lockup at interrupt time can cause such
timeouts)."

So you can see that careful programming is needed in the kernel.

-jwb