RFC: re-enable auto loading of floppy driver when the PNP info says there is a floppy

[Hans de Goede]

Hi,

On 04/12/2010 10:38 PM, Dave Airlie wrote:
> On Mon, 2010-04-12 at 12:18 -0500, Bruno Wolff III wrote:
>> On Mon, Apr 12, 2010 at 12:58:35 -0400,
>>    Kyle McMartin<kyle at mcmartin.ca>  wrote:
>>>
>>> The problem is, EVERYONE has a floppy controller and NOBODY(*) has a
>>> floppy disk drive. PNP only reports the presence of the controller, not
>>> the drive.
>>>
>>> Ergo: FAIL for everyone, for the sake of some ancient crap that nobody
>>> except for a vocal minority of approximately three people cares about.
>>
>> I am not an expert on the tradeoffs on the kernel side and don't have a
>> real strong opinion there. But I do think if floppy drives aren't available
>> by default, there should be some documentation somewhere that tells people
>> how to enable their floppy drives. That isn't necessarily the job of the
>> kernel maintainers.
>>
>> Maybe at first boot people could get asked.
>>
>> Maybe a drive could be looked for once and the result remembered. (I expect
>> that a lot less people move floppy drives around than use them.)
>>
>> Maybe it could be on an FAQ.
>>
>> Maybe it could be mentioned in the release notes. (Though I think this change
>> first affected f12, I don't remember running accross any notice before I
>> first ran into the problem.)
>
> The thing was the window where this patch applied was about 3-4 weeks in
> rawhide, it went in upstream, it slowed boot down on lots of my
> machines, I nuked it.
>
> So Fedora behaviour should not have changed across this patch.
>

Yet it did (change), as udev used to carry a modprobe.conf file which contained
the same alias, and that was dropped when the alias was added to the kernel.

If you look at this F-10 udev build:
http://koji.fedoraproject.org/koji/buildinfo?buildID=105370

You will see the udev package contains a file called:
/etc/modprobe.d/floppy-pnp

With as content:
alias pnp:dPNP0700 floppy

So we do have a change being caused by this patch, as this patch removes
the kernel alias which was to replace the removed udev floppy-pnp modprobe.conf
file.

More interesting though is the question if we can somehow fix this for people
who have a floppy drive without causing the boot delay for people who don't.

When you hit this issue, did you check that your BIOS was configured for you
not having a floppy drive ? In my experience on several machines, the PNP0700
id will go away if you tell the BIOS that there is no floppy drive attached
(in the good old plain CMOS screen, where you can usually also set date / time).

Regards,

Hans