ACPI on Tyan Motherboard

[Stephen Montgomery-Smith]

John Baldwin wrote:
> On 19-Aug-2003 Stephen Montgomery-Smith wrote:
> 
>>I am guessing that this 4 second delay is part of how FreeBSD wants it.  If that 
>>is the case, it shows that the power button is working as it should - it is the 
>>power-down process that is not working right.
> 
> 
> No, the 4 second countdown thing is in the BIOS/hardware and is not OS
> dependent at all.  If the box doesn't properly shut off when you hold
> the power button for 4 seconds, that is a hardware or BIOS bug and
> something FreeBSD has no control over.
> 

FreeBSD must have some control over this process, because in FreeBSD-4.8 and 
RedHat 9.0 (which make no attempt to access ACPI), the power button immediately 
powers down the computer.  The same is also true if I start FreeBSD-current with 
ACPI support switched off.  (Windows 2000 also works fast, but the Windows 2000 
OS first cleanly shuts down the file system.)

But now that people are mentioning this 4 second issue, I have now also noticed 
that if I do "halt -p" under FreeBSD-current, the OS does all its shutdown 
stuff, prints the message "Uptime xxxxx", and then waits about 4 seconds before 
doing its powerdown attempt.



-- 
Stephen Montgomery-Smith
stephen at math.missouri.edu
http://www.math.missouri.edu/~stephen