Re: [PATCH] SCSI midlayer power management

[Nigel Cunningham <ncunningham@linuxmail.org>]

Hi.

On Wed, 2004-08-11 at 23:13, Nathan Bryant wrote:
> >>ACPI S1 and S4/swsusp are untested, but I think there should be no
> >>regressions with S1. To do S1 properly, we probably need to tell the
> >>drive to spin down, and I don't know what the SCSI command is for
> >>that... For S4, the call to scsi_device_quiesce might pose a problem for
> >>the subsequent state dump to disk. But I'm not sure swsusp ever worked
> >>for SCSI.

I tried it on an OSDL machine and could suspend (suspend 2), but only
resume as far as copying back the original kernel. The problem then
looked to me like it was request ids not matching what the drive was
expecting (but I'm ignorant of scsi, so might be completely wrong
there).

> answer is NO. For purposes of not suspending the drivers, I haven't 
> looked into how swsusp would see which host adapter owns which drive, 
> but some of the required information seems to be present in sysfs.

With my 'device tree' code, I'm getting the struct dev of the device
we're using via the struct block_device in the swap_info struct.

Nigel
-- 
Nigel Cunningham
Christian Reformed Church of Tuggeranong
PO Box 1004, Tuggeranong, ACT 2901

Many today claim to be tolerant. But true tolerance can cope with others
being intolerant.