From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phillip Susi Subject: Re: Disk spin-up optimization during system resume Date: Thu, 16 Jan 2014 13:39:26 -0500 Message-ID: <52D8275E.5060100@ubuntu.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120]:33940 "EHLO cdptpa-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751570AbaAPSj2 (ORCPT ); Thu, 16 Jan 2014 13:39:28 -0500 In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Alan Stern , Todd E Brandt Cc: Aaron Lu , Tejun Heo , SCSI development list -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 1/16/2014 11:59 AM, Alan Stern wrote: > Since the START-STOP and TEST UNIT READY (or REQUEST SENSE or > whatever) commands are likely to take a long time, they should all > be carried out asynchronously with respect to the resume procedure. > I don't know what the best way is to implement this. But it is > important to guarantee that in the RPM_ACTIVE case, the START-STOP > command gets sent to the disk before any other commands. (This > isn't an issue in the RPM_SUSPENDED case, as the block layer will > prevent requests being sent out unless they have the REQ_PM flag > set.) We could avoid that problem by having the resume_early issue the start command any time it leaves it in RPM_ACTIVE. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (MingW32) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJS2CdeAAoJEI5FoCIzSKrw9h4H/0P3aefB4/ST10CAtJK0LHl4 iyqu1dXrkLgC3Q827aj+dr5rjjrE1J3oid80/bHyhXA+GB379GU77Tp9IN7XiEhj KxcT3rU/7+ybATDmf8sx96/uuDSOgmyQ8cBw24YCEgobwraBG+K0APgvsKCAnOwF dIq+mamjFBXDXzzfzLFOyM+VTZ0nY4iTcnXW5qAB8sk97Jt3ksfZ7zABfcU3ih4F SqfLu25UIMNV1BYMxwo13Qf3t7j3fEmWSAXOB1/HaaERIxih/lCJc1G5oH7uTAkE Wco6Wd7uEDErJKwXb4tSQ1nFIFoswFBbCpl553TB1YRtAxBWgFGVUWez4U5q/7o= =6Ohk -----END PGP SIGNATURE-----