From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754657AbXDXXrm (ORCPT ); Tue, 24 Apr 2007 19:47:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754658AbXDXXrm (ORCPT ); Tue, 24 Apr 2007 19:47:42 -0400 Received: from shawidc-mo1.cg.shawcable.net ([24.71.223.10]:24799 "EHLO pd3mo3so.prod.shaw.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754657AbXDXXrl (ORCPT ); Tue, 24 Apr 2007 19:47:41 -0400 Date: Tue, 24 Apr 2007 17:47:33 -0600 From: Robert Hancock Subject: Re: old ISA DMA bug in 2.6.12? In-reply-to: To: Bob Tracy Cc: linux-kernel@vger.kernel.org Message-id: <462E9715.60304@shaw.ca> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit References: User-Agent: Thunderbird 2.0.0.0 (Windows/20070326) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Bob Tracy wrote: > I was enjoying yet another session of beating my head against the wall > trying to do useful things with old hardware :-), and managed to cause a > kernel panic by simply trying to mount a cdrom in the context of a DSL-N > installation. > > The SCSI host adapter is an Adaptec AHA-1542B, and when I try to mount a > cdrom, I manage to run afoul of the BAD_DMA() check in aha1542.c: the > buffer returned is not in the lower 16 MB of memory. > > The same 2.6.12 kernel + hardware combination works fine as long as I > confine my I/O to the hard disk that's also attached to the AHA-1542B. Looks like the aha1542 driver doesn't set the DMA mask, so the kernel will default to thinking it can do 32-bit DMA when it should be 24-bit. -- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/