Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262548AbTELSq4 (ORCPT ); Mon, 12 May 2003 14:46:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262562AbTELSq4 (ORCPT ); Mon, 12 May 2003 14:46:56 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:17307 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S262548AbTELSqz (ORCPT ); Mon, 12 May 2003 14:46:55 -0400 Date: Mon, 12 May 2003 20:59:34 +0200 From: Jens Axboe To: "Mudama, Eric" Cc: Oleg Drokin , Bartlomiej Zolnierkiewicz , Alan Cox , Oliver Neukum , lkhelp@rekl.yi.org, linux-kernel@vger.kernel.org Subject: Re: 2.5.69, IDE TCQ can't be enabled Message-ID: <20030512185934.GD17033@suse.de> References: <785F348679A4D5119A0C009027DE33C102E0D31A@mcoexc04.mlm.maxtor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <785F348679A4D5119A0C009027DE33C102E0D31A@mcoexc04.mlm.maxtor.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1219 Lines: 30 On Mon, May 12 2003, Mudama, Eric wrote: > > The only difference between SATA TCQ and PATA TCQ is that in PATA TCQ, the > drive doesn't report the active tag bitmap back to the host after each > command. Other than that they are functionally identical to my > understanding. (Yes, there are options like first-party DMA, but these are > not requirements) You are ignoring the host side of things. PATA TCQ is basically unsupportable without some hardware support (auto-poll). It's my understanding that all SATA controllers do that. Then there's the debate of whether TCQ is worth it at all, in general. I feel that a few tags just to minimize the time spent when ending a request to starting a new one is nice. > Personally I'd like to see the option stay in there as experimental, it > helps us drive folks test stuff when we can just flip an option off/on to > get that functionality. I agree, besides it just needs a bit of fixing, can't be much. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/