Subject: Re: CVS commit: src/sys/dev/ata
To: Charles M. Hannum <mycroft@mit.edu>
From: Cherry G. Mathew <cherry.g.mathew@gmail.com>
List: port-macppc
Date: 04/05/2006 09:10:53
Moving thread to tech-kern, tech-macppc:

On 4/4/06, Charles M. Hannum <mycroft@mit.edu> wrote:
> On Tue, Apr 04, 2006 at 07:11:45AM +0000, Cherry G. Mathew wrote:
> > Sleeps hard disk just before system shutdown.
> > Some hardware (eg: Apple iBooks) don't do this automatically
> > and the harddisk behaves as if the power plug were pulled.
> >
> > Closes PR: kern/32766
>
> This is not an acceptable implementation.  It causes the disks to spin
> down when you're doing a "reboot" -- which puts considerably more wear
> on the drive than an "emergency retract" ever did, and is also really,
> really annoying to wait for.
>
> Furthermore, doing an "emergency retract" was never a big deal in the
> first place.  Who cares?
>

I'm no expert on hard disks but in the case of this particular issue
on the iBook:

- Open Firmware, Linux and MacOSX do not cause this sound ( the
emergency retract) to happen.
- It is a SMART parameter, which means there is some significance to the ev=
ent.

> Please back it out at your earliest convenience.
>

Done, and sorry for the hasty commit.

Since it looks like this is a macppc specific thing, maybe a better
way to do this would be to spin-down the disk in:
machdep.c:cpu_reboot()

Would it be ok to call: wd_standby() directly from here, or does it
need to go through an "apm" wrapper, as is done on i386 ?

--
~Cherry