From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phillip Susi Subject: Re: Disk wakeup on resume Date: Tue, 05 Nov 2013 11:23:33 -0500 Message-ID: <52791B85.1090805@ubuntu.com> References: <527859D9.3030607@ubuntu.com> <52791518.5070705@interlog.com> 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]:50410 "EHLO cdptpa-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754258Ab3KEQXf (ORCPT ); Tue, 5 Nov 2013 11:23:35 -0500 In-Reply-To: <52791518.5070705@interlog.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: dgilbert@interlog.com, linux-scsi@vger.kernel.org, "linux-ide@vger.kernel.org" -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 11/5/2013 10:56 AM, Douglas Gilbert wrote: > I think that you might find that almost any SCSI command > (translated to its ATA equivalent command) will wake up a SATA > disk. Perhaps just this sequence: fd = open() ; > close(fd) ; is sufficient. No, otherwise hdparm, udisks, etc would not be able to issue the CHECK POWER command without waking the disk. Most commands do wake the drive, but as far as I can see, nobody is sending down any, and more importantly, the wake is happening within the kernel pm resume path, not by userspace after resume. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (MingW32) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJSeRuFAAoJEJrBOlT6nu75zOcH/1eKDZW73qiWN5x1mHnkZCx2 +khrRybBM+d6iwsfKODdMPkfXe89QxNxZArPMP60OtCTzfnUuzpK9SfNuzB2CB3p zKX1H5tOQEowUd9A2DpzJmN89UGi/+ZVDEQBlo6byqXKhd/Gj10TuD8vyaHSSadN XYYvWIlreayELaI70uQLdntfHufProdoZQ+kB9pQhvvq8IhtcuARjUeaGbnHxznc UT2SvYeGritndPLzBOAeWw6/WZ/Rvzo5Q9s2nZAWyWnNlrdt95cmLl+56vCP2AJW b4Tf4TrPGbhB0EPFU+vWy6mT4DFReqDbkMvgsWoOrFF8OPgrUx3l+9gWifejLw8= =77FK -----END PGP SIGNATURE-----