Message-ID: <20090201215616.GA24997@frolo.macqel>
Date:	Sun, 1 Feb 2009 22:56:16 +0100
From:	Philippe De Muyter <phdm@...qel.be>
To:	Adam M Belay <abelay@....EDU>
Cc:	Robert Hancock <hancockrwd@...il.com>,
	linux-kernel@...r.kernel.org, bjorn.helgaas@...com
Subject: Re: [BUG] pnpbios breaks floppy support

On Sun, Feb 01, 2009 at 03:48:49PM -0500, Adam M Belay wrote:
> Quoting Robert Hancock <hancockrwd@...il.com>:
>
>> Philippe De Muyter wrote:
>>> 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 Searching the web and the outdated pnp kernel documentation, I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.
>>
>> There's likely another resource with id of PNP0C01 or PNP0C02 (Motherboard 
>> resources) which contains that same IO port range.
>>
>
> Yes, could you post the same information for 00:07 so we can start to 
> narrow
> this down?  Also having "cat /proc/ioports" couldn't hurt.

Here it is, and that shows that you are thus both really experts in that area :

	$ cat 00:07/id 00:07/resources
	PNP0c02
	state = active
	io 0x80-0x80
	io 0x10-0x1f
	io 0x22-0x3f
	io 0x44-0x5f
	io 0x90-0x9f
	io 0xa2-0xbf
	io 0x3f0-0x3f1
	io 0x3f3-0x3f3
	mem 0x100000-0xc0fffff
	mem 0xfff80000-0xfff94fff
	mem 0xfff98000-0xfffbffff
	mem 0xfffc0000-0xffffffff

	$ cat /proc/ioports 
	0000-001f : dma1
	0020-0021 : pic1
	0040-0043 : timer0
	0050-0053 : timer1
	0060-006f : keyboard
	0070-0077 : rtc
	0080-008f : dma page reg
	00a0-00a1 : pic2
	00c0-00df : dma2
	00f0-00ff : fpu
	0170-0177 : 0000:00:07.1
	  0170-0177 : libata
	01f0-01f7 : 0000:00:07.1
	  01f0-01f7 : libata
	02f8-02ff : serial
	0376-0376 : 0000:00:07.1
	  0376-0376 : libata
	0378-037a : parport0
	037b-037f : parport0
	03c0-03df : vga+
	03f0-03f1 : pnp 00:07
	03f3-03f3 : pnp 00:07
	03f6-03f6 : 0000:00:07.1
	  03f6-03f6 : libata
	03f8-03ff : serial
	04d0-04d1 : pnp 00:11
	0cf8-0cff : PCI conf1
	ec00-ec7f : 0000:00:03.0
	  ec00-ec7f : tulip
	ecf0-ecff : 0000:00:07.1
	  ecf0-ecff : libata

Thanks for your quick answers.  Feel free to ask more info's

Philippe
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