From owner-freebsd-current Wed Jul 30 01:29:36 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id BAA18820 for current-outgoing; Wed, 30 Jul 1997 01:29:36 -0700 (PDT) Received: from karon.dynas.se (karon.dynas.se [192.71.43.4]) by hub.freebsd.org (8.8.5/8.8.5) with SMTP id BAA18815 for ; Wed, 30 Jul 1997 01:29:33 -0700 (PDT) Received: (qmail 19021 invoked from network); 30 Jul 1997 08:29:27 -0000 Received: from spirit.dynas.se (HELO host.domain) (172.16.1.10) by karon.dynas.se with SMTP; 30 Jul 1997 08:29:27 -0000 Received: by spirit (Smail3.1.28.1 #32) id m0wtU8M-000JemC; Wed, 30 Jul 97 10:29:26 +0200 Date: Wed, 30 Jul 1997 10:29:26 +0200 (MET DST) From: Mikael Hybsch Reply-To: Mikael Hybsch To: freebsd-current@freebsd.org Subject: Re: aha0: DMA beyond end Of ISA In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@freebsd.org X-Loop: FreeBSD.org Precedence: bulk It now looks as if the problem is in the function scsi_read_capacity() in scsi_base.c. It calls scsi_scsi_cmd() with the address of a local variable (rdcap) as the data_addr argument. By printing &rdcap and vtophys(&rdcap) while trying to mount the cdrom and running programs in the background that allocate memory, the physical address of rdcap eventually exceeded 16M and the mount failed. If the kernel stack is allowed to be allocated above 16M, scsi_read_capacity() needs some special code to handle the BOUNCE_BUFFERS option. On Mon, 28 Jul 1997, I wrote: > I have a 486 with 24M memory and a 1542B connected to a HP 4020i. > > Frequently when I try to access the CD or burn a new CD, I get the message > aha0: DMA beyond end Of ISA: 0x1154d24 > or other addresses above 0x1000000. > > By repeating the mount command it will eventually succeed. > > I'm running 3.0-current as of some days ago and > have the BOUNCE_BUFFERS option in the kernel, so what > could be causing this? -- Mikael Hybsch Email: micke@dynas.se DynaSoft, Dynamic Software AB Phone: +46-8-7250900 Box 10704 Fax: +46-8-6494970 S-121 29 STOCKHOLM, SWEDEN