From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: [PATCH #upstream-fixes] sata_mv: don't issue two DMA commands concurrently Date: Fri, 15 Aug 2008 08:27:27 -0400 Message-ID: <48A5762F.7000502@rtr.ca> References: <489C19CE.6030708@ngs.ru> <489C4B6E.9070306@rtr.ca> <489C4F29.6020007@rtr.ca> <489C54D1.5080901@rtr.ca> <48A29E14.3090908@gmail.com> <48A2BBDC.2090201@ngs.ru> <48A2BC5D.5060801@gmail.com> <48A2C35C.7020400@ngs.ru> <48A2C460.6040504@gmail.com> <48A2C770.2040200@ngs.ru> <48A2CB1B.4000200@gmail.com> <48A2CE09.9090806@ngs.ru> <48A30920.5030803@rtr.ca> <48A33CDC.3000809@ngs.ru> <48A36FE5.5000706@rtr.ca> <48A3E1FF.4030502@ngs.ru> <48A427C0.1070500@rtr.ca> <48A43054.80605@ngs.ru> <48A48C2E.7020902@rtr.ca> <48A5159E.2010508@ngs.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from rtr.ca ([76.10.145.34]:53401 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752749AbYHOM10 (ORCPT ); Fri, 15 Aug 2008 08:27:26 -0400 In-Reply-To: <48A5159E.2010508@ngs.ru> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Artem Bokhan Cc: linux-ide@vger.kernel.org Artem Bokhan wrote: > It uses ncq. Thanks, Mark. .. Okay, so the ATA specs explicitly require a reset there. Not much to do about that. If you were super-keen, though, you could crawl through libata and try reducing various delays and polling intervals that are associated with a hard reset for that specific (ahci?) driver and the core libata routines. Might shave that 0.75sec down to perhaps 100ms or so. But again, the optimal numbers in your specific case will not work for the general case. It might be possible to parameterize it all, though, permitting different values for differing hardware. Cheers