From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 12 Apr 2001 11:17:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 12 Apr 2001 11:17:07 -0400 Received: from mailserver-ng.cs.umbc.edu ([130.85.100.230]:47805 "EHLO mailserver-ng.cs.umbc.edu") by vger.kernel.org with ESMTP id ; Thu, 12 Apr 2001 11:16:54 -0400 To: linux-kernel@vger.kernel.org Subject: IDE DMA under 2.4? From: Ian Soboroff X-Tomato: Polka-dot Date: 12 Apr 2001 11:16:47 -0400 Message-ID: <87itkaup0g.fsf@danube.cs.umbc.edu> User-Agent: Gnus/5.0808 (Gnus v5.8.8) Emacs/20.7 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org i've noticed that i can't seem to enable DMA on my IDE disk under 2.4.2-ac18. this works under 2.2.19pre14 (the last 2.2 kernel i built). i've been slogging through lk archives but can't seem to find where this got changed. when i do 'hdparm -d 1 /dev/hda', i get /dev/hda: setting using_dma to 1 (on) HDIO_SET_DMA failed: Operation not permitted using_dma = 0 (off) my controller is a PIIX4, the disk is an IBM DJSA-220 (2.5" laptop drive, 20GB). is there any way to reenable DMA on this disk? according to 'hdparm -t -T' while booted single-user, i get about 6MB/s without DMA (under 2.4), and about 17MB/s with (under 2.2). tia, and sorry if it's a faq i couldn't dig up, ian -- ---- Ian Soboroff ian@cs.umbc.edu University of MD Baltimore County http://www.cs.umbc.edu/~ian