Re: USB attached SATA disk idle spindown
From: Tejun Heo
Date: Sat Jul 19 2008 - 06:22:57 EST
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
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