From mboxrd@z Thu Jan 1 00:00:00 1970 From: Albert Lee Subject: Re: ide/dma not working from 2.6.19 to 2.6.21 Date: Tue, 26 Jun 2007 13:05:43 +0800 Message-ID: <46809EA7.5090005@tw.ibm.com> References: <7ac1e90c0706210447k7c1bdb26y43d62e930ce7728e@mail.gmail.com> <467A9923.6010203@ru.mvista.com> <467F5127.4060006@tw.ibm.com> <20070625101009.48269d6e@the-village.bc.nu> Reply-To: albertl@mail.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from e34.co.us.ibm.com ([32.97.110.152]:41921 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751456AbXFZFFz (ORCPT ); Tue, 26 Jun 2007 01:05:55 -0400 Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e34.co.us.ibm.com (8.13.8/8.13.8) with ESMTP id l5Q55sqP012361 for ; Tue, 26 Jun 2007 01:05:54 -0400 Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v8.3) with ESMTP id l5Q55sP7267160 for ; Mon, 25 Jun 2007 23:05:54 -0600 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l5Q55rLL011305 for ; Mon, 25 Jun 2007 23:05:54 -0600 In-Reply-To: <20070625101009.48269d6e@the-village.bc.nu> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: albertl@mail.com, Sergei Shtylyov , Bahadir Balban , linux-ide@vger.kernel.org, Mikael Pettersson Alan Cox wrote: >>Reloading the pata_pdc2027x module then the problem goes away. >>I guess maybe somehow mdelay() is not as precise as before... > > > It's not the most accurate of things once power management and the like > get invovled. HT doesn't help it either. You should have get much more > accurate timing information if you query gettimeofday before/after and do > a few loops. > Thanks for the advice. Patch to follow. -- albert