Re: [PATCH] sd: implement stop_on_shutdown

[Tejun Heo <htejun@gmail.com>]

James Bottomley wrote:
> There are practical problems to handling this in sd, namely that the
> power handling commands and state model are part of the ATA command set,
> not part of the SCSI command set.  SAT really only covers the basics of
> mapping the different power management models.

I see.  I think what's currently described in SAT-r09 is enough for most
cases this is necessary - ATA and USB disks.

> However, I suppose if we're going to allow stop on shutdown, it does
> make sense to use it on suspend as well.

Yeah, it does.  Issuing STOP on suspend and START (possibly with
IMMED=1) on resume should do the trick.  libata currently does this
using sht->resume/suspend callbacks but it fits much better in sd in
that it's also useful for other SCSI disks.

James, do you think such change to sd is acceptable?  As the original
patch, the default behavior won't be changed, so unless specifically
configured (probably during boot by dist) there won't be any behavior
change.

Thanks.

-- 
tejun