From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261623AbTDHTUU (for ); Tue, 8 Apr 2003 15:20:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261631AbTDHTUU (for ); Tue, 8 Apr 2003 15:20:20 -0400 Received: from franka.aracnet.com ([216.99.193.44]:54181 "EHLO franka.aracnet.com") by vger.kernel.org with ESMTP id S261623AbTDHTUS (for ); Tue, 8 Apr 2003 15:20:18 -0400 Date: Tue, 08 Apr 2003 12:31:54 -0700 From: "Martin J. Bligh" To: linux-kernel Subject: [Bug 556] New: dma not enabled for IDE hard drives Message-ID: <28110000.1049830314@[10.10.2.4]> X-Mailer: Mulberry/2.2.1 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org http://bugme.osdl.org/show_bug.cgi?id=556 Summary: dma not enabled for IDE hard drives Kernel Version: 2.5.67 Status: NEW Severity: normal Owner: alan@lxorguk.ukuu.org.uk Submitter: freelsjd@ornl.gov Distribution:Debian/Sid Hardware Environment:dual 2.4Ghz Xeon, SE7500CW2 MB, all Intel Promise PDC20267 ATA-100 ide channels in non-RAID mode Software Environment:testing with hdparm 5.2-1 of Debian/Sid Problem Description: I have similar .config settings for both the 2.4.20 and the 2.5.67 kernels with the identical machine. Under 2.4.20, I do get dma enabled and see good performance (Mb/s) from the hard disk I/O. However, under the 2.5.67 kernel, dma is not enabled and the performance of the hard drives is poor (~2-3 Mb/s under 2.5.67 versus ~30 Mb/s under 2.4.20). The "hdparm -I /dev/hda" command confirms that dma is enabled on the hardware, but "hdparm -d1 /dev/hda" confirms that dma will not enable and the performenace is poor under 2.5.67. Under 2.4.20, these same commands show good performance. Steps to reproduce: make the kernel, run lilo, boot, and run hdparm tests on this machine.