CAM suspend

[Walter C. Pelissero]

Having noticed that there is not a big interest in it, among the
fellow FreeBSDers, I was about to set off and hack up the scsi
subsystem to implement spindown on suspend and spinup on resume of the
da devices, when I realized that there seems to be no hook in the SCSI
code for this events.

I'm not a device driver expert, so I'm looking for clues.

What I mean is that the ata-pci driver, for instance, specifies hooks
via the device_method_t structure which is not available in the
scsi_all or scsi_da modules.  I understand that they are simply
different kind of beasts (sitting on different layers of the kernel
code), but I was wondering if there might be a similar mechanism to do
what I want.

So, what is the recommended way (if there is one), to hook a function
of the SCSI subsystem to an event like suspend/resume?

I would most appreciate if anyone could point me to a suitable
document or even anything related to FreeBSD kernel hacking.

Cheers,

-- 
walter pelissero
http://www.pelissero.de