[parisc-linux] Power LED

Helge Deller deller@gmx.de
Tue, 19 Feb 2002 12:11:01 +0100

On Tuesday 19 February 2002 09:50, Hinrich Aue wrote:
> I use 2.4.17-pa26
> I tried to increase push-time to 5*HZ.
> But as you said, the machine doesn't seem to recognize
> when I release the button. 


> So the shutdown is
> initiated correctly, but after 5 sec the machine shuts
> down, ignoring whether the runlevel 6 is reached or
> not.

process_shutdown() calls after 5 seconds poweroff(), which in
turn calls deferred_poweroff() again. deferred_poweroff() then
sends the SIGINT signal to the init process which then
initiates the normal shutdown. There is no other kernel-code
which powers off your computer directly.
This works perfectly for me on the 715/64 and many others here.
Maybe your PDC (BIOS/Firmware) handles that differentlly ? Maybe
you could verify that you have the most recent PDC version ?

> BTW why does the halt command not shut down the
> machine?

I've not found any direct PDC (BIOS/Firmware) call which does this.
pdc_soft_power_shutdown() doesn't seem to do want it's name
suggests. It instead seems to set a flag in the PDC so that when 
you reboot your system it will shut off during the main PDC tests. 
So there seems to be a way to turn off the system immediately,
but it seem to be _very_ system dependant too.

> I heared it would work. :-<
> Is it possible to change the bit 0 if CPU diagnose
> register 25 by hand?

I tried it, but it didn't worked.
If we would find a way to reset bit 0 in reg 25 we would
have a solution.