From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: AHCI NCQ on ESB2 (8086:2681) Date: Mon, 01 Jan 2007 12:20:38 +0900 Message-ID: <45987E06.1070101@gmail.com> References: <4597B34C.1090606@omega71.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from an-out-0708.google.com ([209.85.132.250]:58616 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754226AbXAAK1c (ORCPT ); Mon, 1 Jan 2007 05:27:32 -0500 Received: by an-out-0708.google.com with SMTP id b33so1578714ana for ; Mon, 01 Jan 2007 02:27:31 -0800 (PST) In-Reply-To: <4597B34C.1090606@omega71.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: yahoo-groups@omega71.com Cc: linux-ide@vger.kernel.org Bryan Boatright wrote: > > I hope this is an appropriate place to ask this question. Googling for > answers turned up nothing. > > I am using kernel 2.6.19.1 and am trying to get NCQ support working. My > Intel chipset (ESB2, see details below) should support NCQ, but it is > not returning the NCQ capabilities bit in the HBA Capabilities > register. Here's the relevant dmesg output: Please test the latest Linus git-tree. ahci used to clear CAP while resetting controller expecting it to set supported feature bits again. Apparently some controllers don't do it resulting in disabled NCQ. This was fixed recently by the following commit. Commit: 551c012d7eea3dc5ec063c7ff9c718d39e77634f Author: Tejun Heo 2006-12-12 20:17:32 Committer: Jeff Garzik 2006-12-17 00:13:29 Branches: upstream-fixes, upstream, quilt-init Follows: v2.6.19 Precedes: [PATCH] ahci: do not mangle saved HOST_CAP while resetting controller Do not mangle with HOST_CAP while resetting controller. The code is there for a historical reason. The mangling breaks controller feature detection and 0 PORTS_IMPL workaround code. This problem was spotted by Manoj Kasichainula. Signed-off-by: Tejun Heo Cc: Manoj Kasichainula Signed-off-by: Jeff Garzik Happy new year. -- tejun