does udev really require hotplug?

does udev really require hotplug?

[Andrea Barisani]

Hi everybody and happy new year!

Just one simple question about a very simple matter that right now 
I can't figure out: does udev need hotplug package presence?

>From your README:

  If for some reason you do not install the hotplug scripts, you must tell the
  kernel to point the hotplug binary at wherever you install udev at.  This can
  be done by:
	echo "/sbin/udev" > /proc/sys/kernel/hotplug


...does this work properly? It's not clear if some features are lost by not having 
hotplug script installed. Also is this policy subject to changes in the near
future?


Bye and thanks

P.S.
please CC me since I'm not subscribed

-- 
Andrea Barisani <lcars@gentoo.org>                            .*.
Gentoo Linux Infrastructure Developer                          V
                                                             (   )
GPG-Key 0x864C9B9E http://dev.gentoo.org/~lcars/pubkey.asc   (   )
    0A76 074A 02CD E989 CE7F AC3F DA47 578E 864C 9B9E        ^^_^^

Re: does udev really require hotplug?

[Greg KH]

On Fri, Jan 02, 2004 at 11:10:51AM +0100, Andrea Barisani wrote:
> 
> Hi everybody and happy new year!
> 
> Just one simple question about a very simple matter that right now 
> I can't figure out: does udev need hotplug package presence?
> 
> >From your README:
> 
>   If for some reason you do not install the hotplug scripts, you must tell the
>   kernel to point the hotplug binary at wherever you install udev at.  This can
>   be done by:
> 	echo "/sbin/udev" > /proc/sys/kernel/hotplug
> 
> 
> ...does this work properly?

It should.  Does it not for you?

> It's not clear if some features are lost by not having hotplug script
> installed.

None of the other programs that hook off of the hotplug program will be
available to you if you do this (automatic driver loading, firmware
loading, devlabel, etc.)

> Also is this policy subject to changes in the near future?

What policy?  If you don't have the hotplug package installed, then you
can still use udev.  If you have the hotplug package installed, I've
detailed how you can still use udev.  What's the problem?  :)

thanks,

greg k-h

Re: does udev really require hotplug?

[Andrea Barisani]

On Fri, Jan 02, 2004 at 12:19:05PM -0800, Greg KH wrote:
> On Fri, Jan 02, 2004 at 11:10:51AM +0100, Andrea Barisani wrote:
> > 
> > Hi everybody and happy new year!
> > 
> > Just one simple question about a very simple matter that right now 
> > I can't figure out: does udev need hotplug package presence?
> > 
> > >From your README:
> > 
> >   If for some reason you do not install the hotplug scripts, you must tell the
> >   kernel to point the hotplug binary at wherever you install udev at.  This can
> >   be done by:
> > 	echo "/sbin/udev" > /proc/sys/kernel/hotplug
> > 
> > 
> > ...does this work properly?
> 
> It should.  Does it not for you?
> 
> > It's not clear if some features are lost by not having hotplug script
> > installed.
> 
> None of the other programs that hook off of the hotplug program will be
> available to you if you do this (automatic driver loading, firmware
> loading, devlabel, etc.)
> 
> > Also is this policy subject to changes in the near future?
> 
> What policy?  If you don't have the hotplug package installed, then you
> can still use udev.  If you have the hotplug package installed, I've
> detailed how you can still use udev.  What's the problem?  :)
> 
> thanks,
> 
> greg k-h

Ok, now it's all clear :). It wasn't so clear from the documentation (at
least for me) and since I'm not fully familiar with hotplug features I've
decided to ask ;).

Thanks a lot for your feedback

Bye


-- 
Andrea Barisani <lcars@gentoo.org>                            .*.
Gentoo Linux Infrastructure Developer                          V
                                                             (   )
GPG-Key 0x864C9B9E http://dev.gentoo.org/~lcars/pubkey.asc   (   )
    0A76 074A 02CD E989 CE7F AC3F DA47 578E 864C 9B9E        ^^_^^

Re: does udev really require hotplug?

[Jon Smirl]

The new dri drivers I am working on will require hotplug when they are finished.
They use the hotplug event to reset secondary adapters and get the monitor
EDID/DDC data. The drivers don't require udev but will use it if present.

--- Andrea Barisani <lcars@gentoo.org> wrote:
> On Fri, Jan 02, 2004 at 12:19:05PM -0800, Greg KH wrote:
> > On Fri, Jan 02, 2004 at 11:10:51AM +0100, Andrea Barisani wrote:
> > > 
> > > Hi everybody and happy new year!
> > > 
> > > Just one simple question about a very simple matter that right now 
> > > I can't figure out: does udev need hotplug package presence?


=====
Jon Smirl
jonsmirl@yahoo.com

__________________________________
Do you Yahoo!?
Find out what made the Top Yahoo! Searches of 2003
http://search.yahoo.com/top2003

Re: does udev really require hotplug?

[Martin Schlemmer]

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On Sat, 2004-01-03 at 00:56, Andrea Barisani wrote:
> On Fri, Jan 02, 2004 at 12:19:05PM -0800, Greg KH wrote:
> > On Fri, Jan 02, 2004 at 11:10:51AM +0100, Andrea Barisani wrote:
> > > 
> > > Hi everybody and happy new year!
> > > 
> > > Just one simple question about a very simple matter that right now 
> > > I can't figure out: does udev need hotplug package presence?
> > > 
> > > >From your README:
> > > 
> > >   If for some reason you do not install the hotplug scripts, you must tell the
> > >   kernel to point the hotplug binary at wherever you install udev at.  This can
> > >   be done by:
> > > 	echo "/sbin/udev" > /proc/sys/kernel/hotplug
> > > 
> > > 
> > > ...does this work properly?
> > 
> > It should.  Does it not for you?
> > 
> > > It's not clear if some features are lost by not having hotplug script
> > > installed.
> > 
> > None of the other programs that hook off of the hotplug program will be
> > available to you if you do this (automatic driver loading, firmware
> > loading, devlabel, etc.)
> > 
> > > Also is this policy subject to changes in the near future?
> > 
> > What policy?  If you don't have the hotplug package installed, then you
> > can still use udev.  If you have the hotplug package installed, I've
> > detailed how you can still use udev.  What's the problem?  :)
> > 
> > thanks,
> > 
> > greg k-h
> 
> Ok, now it's all clear :). It wasn't so clear from the documentation (at
> least for me) and since I'm not fully familiar with hotplug features I've
> decided to ask ;).
> 

You do know that latest unstable initscripts from Gentoo _do_ support
udev with or _without_ hotplug?  If you have any further issues, please
give me a shout.


Thanks,

-- 
Martin Schlemmer

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Re: does udev really require hotplug?

[Martin Schlemmer]

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On Fri, 2004-01-02 at 12:10, Andrea Barisani wrote:
> Hi everybody and happy new year!
> 
> Just one simple question about a very simple matter that right now 
> I can't figure out: does udev need hotplug package presence?
> 
> >From your README:
> 
>   If for some reason you do not install the hotplug scripts, you must tell the
>   kernel to point the hotplug binary at wherever you install udev at.  This can
>   be done by:
> 	echo "/sbin/udev" > /proc/sys/kernel/hotplug
> 
> 
> ...does this work properly?

Yes, you just miss all other events that hotplug usually handles, and
not udev ...

>  It's not clear if some features are lost by not having 
> hotplug script installed. Also is this policy subject to changes in the near
> future?
> 

I do not think so, but Greg will have to comment ...


-- 

Martin Schlemmer




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