Re: USB attached SATA disk idle spindown

[Tejun Heo <tj@kernel.org>]

Stefan Richter wrote:
> (adding Cc: linux-usb and Johannes Niess)
> 
> On 6/24/2008 6:59 AM, Jonathan Steinert wrote at LKML:
>> Dear list,
>>
>> I am looking for what the current state of USB SATA timed spindown of-
>> disks is ata this time. I've been reading documents and mailing lists-
>> for every possible search I can dream up on the subject. Suggested-
>> workable solutions include (but are probably not limited to):
>>
>> $ hdparm -S
>>     This seems to be the ATA way of telling a disk to spin down, and it
>>     works in some situations, but doesn't appear to work on USB attached
>>     disks under 2.6.25
>>
>> $ sdparm
>>     This is suggested in a small number of locations. Most of which have
>>     examples on how to disable STANDBY on a handful of devices. I am
>>     unable to find any evidence that it can actually be used to enable
>>     power saving.
> 
> I think either of these depend on specific support by the USB to SATA
> bridge firmware.
> 
> I hear some newer bridges and their firmwares implement ATA
> pass-through.  Would that help?

Yeah, ATA pass through is all that's needed for hdparm -S to work.

-- 
tejun