[kde-linux] stop empty floppy drive announcement

[Duncan]

Felix Miata posted on Tue, 12 Nov 2013 16:06:27 -0500 as excerpted:

> On 2013-11-11 23:43 (GMT-0500) Felix Miata composed:
> 
>> How? Every time I login, focus is stolen from Konsole's restoration by
>> the inane popup announcing the presence of a floppy drive with no media
>> in it.
> 
> This is an unresolved bug with likely upstream roots if not entirely:
> https://bugs.kde.org/show_bug.cgi?id=318061

The root problem is one of legacy hardware (lack of) features.  Floppy 
drives are old enough they predate the hardware removable-media-detect 
feature found on, for example, optical (CD/DVD) devices.  The only 
information the BIOS makes available is that there's a device there, and 
the only way to see whether there's actually anything in it is to try it.

Making problems worse, there's no media-change-detect notification 
either, so once a floppy is inserted, it can be switched out without 
anything at the software level realizing it, so if it goes to write to 
the device (or even seek to a different place in the file you had open 
for reading), for all it knows the physical media has been switched out 
and it's reading/writing an entirely different file on the new media now!

The only way to be sure that isn't happening is to actually stat the file 
and compare the results to the ones from before to make sure it's the 
same thing, before each read/write access.

And because floppy drives are so physically SLOW, that introduces a delay 
as the device is physically accessed.

At least on CD/DVD devices, while the media-presence/change detection is 
rather crude by modern standards, it exists, and the way change detection 
is typically supported in software is by polling -- back in the HAL days 
(before udisks, as I said earlier in the thread I have those features 
disabled now and haven't followed what the current solution does) there 
was a notorious feature that polled the CD/DVD hardware every two seconds 
to be sure it hadn't changed -- it was crude, but because the hardware 
could answer without actually spinning up the disk to check, it was 
comparatively fast and normally happened in the background without 
disturbing the user.

Unfortunately, that doesn't work for a floppy, because the device has to 
actually re-read the physical media to check whether it has changed, 
triggering an audible click and likely a UI-stall as the floppy spins up 
and the drive actually rereads the physical sector to see if it's the 
same as before.  Not only would that constant click every couple seconds 
be extremely irritating, it would wear out a floppy in the drive very 
fast (perhaps an hour or two) and would likely kill the drive itself 
within a few days.

So that solution, while viable for CD/DVDs that retain that info in the 
hardware and can simply return it when queried every couple seconds, is  
not viable at all for floppy device hardware.


But as I said in the first reply, the world has thankfully moved on and 
few machines have floppies any more -- or in the event that they do, 
they're often the USB attached version and thus can be physically 
unplugged unless they're actually in use.


In my opinion, probably the best way for software like kde's device 
notification is to ignore floppies entirely.  Just skip anything that the 
BIOS reports as a floppy.  Sure, that means no notification for floppies 
at all, but floppy hardware itself is so old it simply wasn't designed 
with this sort of feature in mind in the first place, and it's best to 
just let sleeping floppies lie.  Fortunately they're now rare, and 
anybody (like Felix) who *IS* still using them is surely used to the 
limitations of the technology and can cope with it.

That's better than forcing users to choose between support that is at 
best broken for floppies, and disabling auto-detect/auto-mount for 
/everything/, thus losing the feature for newer (non-floppy) hardware 
that /does/ support the feature well, or at least like CD/DVDs, can 
answer a poll in firmware without having to physically spinup the media.

But... the same rarity that means few users deal with the problem also 
means few developers actually have the hardware to test with, either.  
And it's kinda hard to properly set up the floppy-ignore, if you don't 
have a floppy device to actually work with to see what you need to 
ignore, and to test to see if your proposed solution is actually going to 
work in practice or not.


Meanwhile, Felix, don't take this the wrong way as I wouldn't presume to 
tell you that can't setup and use your systems as you like, but...

What /is/ your actual use case for floppies?  I was thinking about it and 
trying to come up with some scenario, some use-case, where I might find 
floppies a continued viable solution, and I'm simply coming up dry, 
especially where you're not simply using legacy hardware that you still 
have, but are actually buying and attaching new floppy drives to any 
motherboards that continue to support it, on new installations.  I just 
can't see the use-case where that's justified.

And even if I had a collection of existing floppies and didn't want to 
put all of the data for 1000+ of them on a $2 2-gig USB thumbdrive, I'd 
buy the USB-attached floppy-drives that I could plug-in when needed (and 
just as importantly, unplug when NOT needed), and thus wouldn't have to 
deal with the problems of an internally attached floppy-drive.  If you're 
booting from floppy, anything remotely new should support booting from 
USB-attached floppy as well as it does booting from direct-attached 
floppy, and if we're talking hardware that's old enough it doesn't 
support booting from USB, then it's also old enough that buying new 
floppy-drives and attaching them to it, as you said you do when you can, 
doesn't make sense either.

I just don't see the case where either USB thumbdrives, or CD/DVD read/
writers (of comparable cost to floppy devices, possibly even cheaper 
since the antique-hardware tax that applies to floppy devices isn't as 
steep for CD/DVD writers yet), or worst-case, USB-attached floppies, 
doesn't make more sense than legacy mobo flat-cable-attached floppy-
devices.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman