From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751028AbVH3Gsi (ORCPT ); Tue, 30 Aug 2005 02:48:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751038AbVH3Gsi (ORCPT ); Tue, 30 Aug 2005 02:48:38 -0400 Received: from gate.crashing.org ([63.228.1.57]:34775 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S1750998AbVH3Gsi (ORCPT ); Tue, 30 Aug 2005 02:48:38 -0400 Subject: Re: Ignore disabled ROM resources at setup From: Benjamin Herrenschmidt To: "David S. Miller" Cc: jonsmirl@gmail.com, linux-kernel@vger.kernel.org, greg@kroah.com, helgehaf@aitel.hist.no, torvalds@osdl.org In-Reply-To: <20050829.223238.18109086.davem@davemloft.net> References: <200508261859.j7QIxT0I016917@hera.kernel.org> <1125369485.11949.27.camel@gaston> <9e47339105082921356543098c@mail.gmail.com> <20050829.223238.18109086.davem@davemloft.net> Content-Type: text/plain Date: Tue, 30 Aug 2005 16:43:46 +1000 Message-Id: <1125384226.11949.70.camel@gaston> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2005-08-29 at 22:32 -0700, David S. Miller wrote: > From: Jon Smirl > Date: Tue, 30 Aug 2005 00:35:11 -0400 > > > As far as I can tell no one has built recent hardware this way. But I > > believe there are some old SCSI controllers that do this. I provided a > > ROM API for disabling sysfs access, if we identify one of these cards > > we should just add a call to it's driver to disable ROM access instead > > of bothering with the copy. Currently the copy is not being used > > anywhere in the kernel. > > Qlogic ISP is one such card, but there are several others. > > I think enabling the ROM is a very bad idea, since we in fact > know it disables the I/O and MEM space decoders on a non-empty > set of PCI cards. This is why pci_map_rom is under driver control. There is still a potential issue with userland using the "rom" file in sysfs, which is why we probably should cleanup the pci_map_rom_copy to have the kernel read the ROM once & backstore it upon request from the driver so that further userland accesses will not toggle the real ROM enable. Ben.