Re: CVS commit: src/sys/kern

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Thu, Feb 21, 2008 at 02:57:54PM +0100, Manuel Bouyer wrote:
> We had a similar issues some time ago, where disk would be spun down on
> reboot or halt without powerdown. My conclusion was that drivers needs to
> know what kind of suspend we're doing (suspend, reboot, halt, poweroff) to
> take appropriate action (which may not always be to power off the device).
> At this time, the disk issue was fixed by a hack using global variable.
> But I still believe drivers needs to get more informations from PMF to
> know what's going on.

I still haven't seen any other example that needs to distinguish between
reboot, halt or poweroff. That makes it sounds like a specific hack for
"hard disks" is actually preferable.

The console device is quite a different beast:
(1) console devices normally are required to work during early boot as
well, so they have to have few assumptions about the state of the
system.
(2) console devices do have hooks for "request operation". This hooks
can easily also deal with power management of the parent devices. That
is a completely disjunct issue.

Joerg