From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [RFC] add DMA setup FIS auto-activate feature Date: Thu, 23 Jul 2009 14:45:17 +0900 Message-ID: <4A67F8ED.2070204@kernel.org> References: <1248320734.9035.22.camel@sli10-desk.sh.intel.com> <4A67E00F.40808@pobox.com> <20090723054007.GA7473@sli10-desk.sh.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:32945 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751620AbZGWFp1 (ORCPT ); Thu, 23 Jul 2009 01:45:27 -0400 In-Reply-To: <20090723054007.GA7473@sli10-desk.sh.intel.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Shaohua Li Cc: Jeff Garzik , linux-ide Shaohua Li wrote: >> IIRC, not all NCQ-capable controllers support this feature... SATA 1.0 >> hardware may not behave properly in response, no? > It appears the AHCI spec doesn't define a HBA capability about this > feature, but I'm likely wrong as I'm not quite familar with SATA. IIRC, AA is in the ahci spec from rev 1.0, so if controllers implement the spec correctly, it should work. But even for ahcis, if we enable it by default, I'm fairly sure we'll be met by a number of unpleasant surprises. Not sure whether doing that would be worth the trouble or not. Thanks. -- tejun