Re: Power management for SCSI

[Stefan Richter]

Oliver Neukum wrote:
> Am Mittwoch 13 August 2008 16:59:23 schrieb Alan Stern:
[Quoting Oliver:  true SCSI busses can be shared. So are we using the
correct approach?]
>> This is a good question.  Most USB mass-storage devices do not act as a
>> true SCSI bus, but I believe there are a few non-standard ones that do
>> -- the USB device really contains a SCSI host and arbitrary SCSI
> 
> OK, but does it make sense to have SCSI autosuspend? Or should autosuspend
> operate on the bus the _host_ is connected to (usb, pci, ...)?

In Alan's patch, SCSI calls scsi_host_template methods (if the LLD
provides ones) to suspend and resume a Scsi_Host.  The LLD can use them
to work with the underlying infrastructure to determine what can be done
at that time.  I.e. are there other protocols or other initiator-like
nodes sharing the link?  If yes or if "maybe yes", the infrastructure
keeps the link up.  If not, it can move it into a low-power state.
-- 
Stefan Richter
-=====-==--- =--- -==-=
http://arcgraph.de/sr/
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