Re: Future devfs plans

From: David Bryson
Date: Tue Jul 27 2004 - 12:00:37 EST


On Sun, Jul 25, 2004 at 11:58:32PM -0700 or thereabouts, Erik Steffl wrote:
> >devfs allowes you to not have the driver loaded till you try to use it.
> >so udev _cannot_ do what devfs does.
> >
> >still I agree that the way kernel/hotplug/udev work is much better and
> >supporting the old style devfs works is not necessary. but please be
> >honest about the differences.
>
> which means that now iPod automatically connects to firewire (and
> looses info on random tracks, sometime some other settings), instead of
> only connecting when I try to actually access it (the device).
>

I have been using ipods with linux for about 3 years.
And I see that it says "do not disconnect" even after I have unmounted
the file system. I just disconnect it at this point and have not
had any problems.

> it looks like there is no user level (end user, not admin) control on
> when the device drivers are loaded anymore - or is there?
>
> Is there any way to load drivers on demand (obviously it's not job of
> udev but whose job it is?). What about unloading them - I unmount the
> disk and i think the iPod is disconnecred but it still says connected -
> is there any way to disconnect it (I guess similar problems arise with
> other hotplug devices)
>

This has been discussed in length on lkml many times during the
writing of udev. IIRC the argument was something like:
"we shouldn't be unloading modules because the memory taken up by a
module in memory(a few k) isn't worth writing the code to save"

I also recall there was something about end user behavior, but I don't
remember the details. Read the archives.

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