Re: WLAN-Card on Sarge

[Bill Moseley <moseley@hank.org>]

On Sat, Jun 12, 2004 at 01:18:34PM +0200, Thomas Hood wrote:
> cardmgr manages PCMCIA cards via /etc/pcmcia/network.
> 
> Hotplug can do the same thing but it is disabled by default.  If you
> enable the hotplug mechanism by adding
> 
>     mapping hotplug
>     script echo

Ok, so hotplug then does an ifup eth0=hotplug, the script "echo" simply
echos the physical interface (eth0 in this example) and then the 
"iface eth0" stanza is brought up.


> to /etc/network/interfaces then you should disable the cardmgr
> mechanism by putting an
> 
>     exit 0
> 
> at the top of /etc/pcmcia/network.

Ok, but in this case the pcmcia (cardmgr) setup is managing loading and
unloading and required modules.

So, what's the advantage of using hotplug for bringing up the interface
over cardmgr running /etc/pcmcai/network(.opts)?


> > In my network.opts script I modified it to bring down eth0 before
> > bringing up the wireless interface (eth1 in my case), and when the card
> > is removed call ifup eth0.  What I'd like to figure out is how to not
> > bring up eth0 unless a cable is plugged in.
>  
> You can use ifplugd for that.

I tried that once, and maybe didn't understand the config.  I was
actually looking for a way in /etc/network/interfaces to run a script
and have the exit code control how the interface is brought up.  Maybe I
wasn't thinking clearly and I could rather have the script return an
undefined map name if the ethernet cable is not detected.

> It is most likely buggy drivers causing lockups.

Ok.  But the problems really started after upgrading to 2.6 kernel, but
that's when I also moved from wlan-ng to Orinoco.

I asked on Seattle Wireless list about best driver for Linux.  Someone
suggested "hands down" HostAP.  But the debian page for hostap says to
use wlan-ng:

  However, the orinoco_cs driver in current 2.4 kernel tree or
  pcmcia-cs package or linux-wlan-ng is probably better supported
  solution for cases that do not use Host AP mode.

So I'm not sure.  I just want to find the best driver/card mix for the
least amount of trouble.  I'll buy the wireless card to fit the driver.

> Expect further problems.  Debian's support for dynamic configuration sucks.
> To gain an understanding of how badly it sucks, start reading the bugs
> open against hotplug and ifupdown.

Is that a Linux issue or Debian?

I did notice that with 2.4.21 and wlan-ng that cardmgr was better at
removing the card -- I'd pull the card and the drivers would be removed
without delay.  Now with 2.6.5 and Orinoco|HostAP there's either a long
delay or a system hang.  I don't think that's a cardmgr issue, though --
as I've tried manually removing the drivers (ifdown eth1; rmmod
<driver>) and have the same problems.  So, I'll agree that it's either a
problem with the driver dealing with being removed, or the kernel.

It's time like these that those powerbooks don't seem so expensive. ;)



-- 
Bill Moseley
moseley@hank.org