From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753345AbZBANST (ORCPT ); Sun, 1 Feb 2009 08:18:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751395AbZBANSJ (ORCPT ); Sun, 1 Feb 2009 08:18:09 -0500 Received: from mailrelay007.isp.belgacom.be ([195.238.6.173]:17100 "EHLO mailrelay007.isp.belgacom.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751370AbZBANSI (ORCPT ); Sun, 1 Feb 2009 08:18:08 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Al4FANYvhUnCTtAn/2dsb2JhbACBbsUDhBQG Date: Sun, 1 Feb 2009 14:18:01 +0100 From: Philippe De Muyter To: Robert Hancock Cc: linux-kernel@vger.kernel.org, abelay@mit.edu, bjorn.helgaas@hp.com Subject: Re: [BUG] pnpbios breaks floppy support Message-ID: <20090201131801.GA326@frolo.macqel> References: <20090131212915.GA19276@frolo.macqel> <49854A71.500@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49854A71.500@gmail.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Feb 01, 2009 at 01:08:33AM -0600, Robert Hancock wrote: > Philippe De Muyter wrote: >> Hello linux experts, >> Today I tried to upgrade a PC's kernel from 2.6.11 to 2.6.22, and >> I saw some strange messages when booting : >> Floppy drive(s): fd0 is 1.44M >> floppy0: Floppy io-port 0x03f2 in use >> Previously, I had : >> Floppy drive(s): fd0 is 1.44M >> FDC 0 is a post-1991 82077 >> Needless to say, my floppy hardware works perfectly, and my floppy >> was usable with the old kernel, while the floppy is now inaccessible >> with the new kernel. Even /dev/fd0 does not exist anymore. >> Searching for a cause to that problem, I saw the following messages >> before the floppy probe in the new kernel : >> PnPBIOS: Scanning system for PnP BIOS support... >> PnPBIOS: Found PnP BIOS installation structure at 0xc00fd5e0 >> PnPBIOS: PnP BIOS version 1.0, entry 0xf0000:0x5ba3, dseg 0xf0000 >> PnPBIOS: 17 nodes reported by PnP BIOS; 17 recorded by driver >> [...] >> pnp: 00:07: ioport range 0x3f0-0x3f1 has been reserved >> pnp: 00:07: ioport range 0x3f3-0x3f3 has been reserved >> [...] >> Searching the web and the outdated pnp kernel documentation, I >> finally found an option to add to my kernel parameters line : >> pnpbios=off >> Now my floppy works again, but I am not really satisfied. >> What do I loose with the 'pnpbios=off' option ? >> Isn't there a smoother option to allow pnpbios but avoiding to reserve >> floppy's io-ports ? >> Should I modify rather /drivers/block/floppy.c or /drivers/pnp/*.c >> to make pnpbios and floppy driver coexist peacefully ? And is there >> an example of such modifications for other standard peripherals ? > > Presumably the problem is that your BIOS marks the IO ports used by the > floppy controller as reserved which prevents the floppy driver from binding > to them. (2.6.11 probably was before we even processed PnP reserved > regions.) > > I think we now have handling for the case where the reservations overlap > PCI devices, but I think it's the first I've heard of them overlapping the > floppy IO ports.. I should have added that, when started with pnpbios enabled, I have found the following in /sys/devices/pnp0/ : $ cat 00:03/id PNP0700 $ cat 00:03/resources state = active io 0x3f4-0x3f5 io 0x3f2-0x3f2 irq 6 dma 2 $ cat 00:03/options port 0x3f4-0x3f4, align 0x0, size 0x2, 16-bit address decoding port 0x3f2-0x3f2, align 0x0, size 0x1, 16-bit address decoding irq 6 High-Edge dma 2 8-bit compatible AFAIK, PNP0700 is the pnp id for the standard floppy disk, and the resources and options files describe the expected io-ports of the floppy disk, so this does not seem to be an error in the bios. Philippe