Porting code from the Linux ibm-acpi sourceforge package

[Kevin Oberman]

> Date: Sun, 08 May 2005 13:46:33 -0700
> From: Nate Lawson <nate at root.org>
> Sender: owner-freebsd-acpi at freebsd.org
> 
> Takanori Watanabe wrote:
> > In message <20050508024448.A943 at cons.org>, Martin Cracauer $B$5$s$$$o$/(B:
> > 
> >>Hi,
> >>
> >>I reinstalled my Thinkpad R40 with FreeBSD-5-stable.  Works very well
> >>except for video corruption on sleep and that I miss some ACPI
> >>functionality I had with the ibm-acpi package under Linux.
> > 
> > 
> > Some functionalies are implimented in acpi_ibm.
> 
> In particular, sys/dev/acpi_support/acpi_ibm.c
> If you want to update that, it would be good since Linux appears to have 
> reverse engineered more capabilities recently.
> 
> >>More specifically, I would like to port or reimplement some parts of
> >>it, and I would like to start with the code to eject and re-mount the
> >>ultrabay devices.
> >>
> >>I have the Linux code in front of me which is showing, for the example
> >>of the basic bay identifier and the eject code:
> >>
> >>IBM_HANDLE(bay, root,
> >>          "\\_SB.PCI.IDE.SECN.MAST",   /* 570 */
> >>          "\\_SB.PCI0.IDE0.IDES.IDSM", /* 600e/x, 770e, 770x */
> >>          "\\_SB.PCI0.IDE0.SCND.MSTR", /* all others */
> >>);                                      /* A21e, R30, R31 */
> >>IBM_HANDLE(bay_ej, bay,
> >>          "_EJ3",                 /* 600e/x, A2xm/p, A3x */
> >>          "_EJ0",                 /* all others */
> >>);                                 /* 570,A21e,G4x,R30,R31,R32,R40e,R50e */
> > 
> > But eject handling is not supported .
> 
> There is a lot of work to do here and not much of it has to do with 
> ACPI.  I have a patch for ACPI eject support that I'll post again some 
> time.  But it is not usable since many device drivers don't support 
> eject.  For instance, our ATA driver did not support detach until the 
> recent mkIII import.  I'm not sure if it supports forced detach yet. 
> Going up a level, I'm not sure how our filesystem drivers would support 
> a drive disappearing out from under them.  If you want to contribute, I 
> think a good first step is adding a testing SYSCTL_PROC that calls
> device_detach(devclass_get_device(devclass_find("acd"), 0)) and then 
> running it to see if it works.
> 
> Linux doesn't yet implement a proper device tree (although they're 
> getting better).  So they have to have lots of hacks like these handle 
> arrays to figure out what to eject.  In FreeBSD, the ACPI side is very 
> simple -- you get a notify, take the passed in handle, and call the 
> associated device_t's detach routine.  That's what my patch does.  No 
> hardcoded paths.

FreeBSD ATA has supported bus detach since ATAng (whenever that was). I
have had no problem detaching ATA bus 1 and removing the drive (CD or
HD) in the bay and replacing it with another or with a battery. Of
course, it MUST be dismounted before the detach or a panic is to be
expected.

Also, if you use a second battery, you must have it in the system at
boot time or it won't be seen, used, or even charged. If you boot with
the battery, you can:
atacontrol detach 1
remove the battery
insert a disk drive
atacontrol attach 1
use the disk and dismount it.
atacontrol detach 1
remove the disk
insert the battery
Battery will be seen and used

This should work in V5.3, -stable, or -current, although I have not
run v5 on my T30 for some time.
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net			Phone: +1 510 486-8634