From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johannes Berg <johannes@sipsolutions.net>
Subject: Re: [RFC][PATCH] Fix another namespace issue with devices assigned
 to  classes
Date: Mon, 07 Jun 2010 14:36:45 +0200
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Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
	Greg KH <greg@kroah.com>, netdev <netdev@vger.kernel.org>
To: Kay Sievers <kay.sievers@vrfy.org>
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On Mon, 2010-06-07 at 14:26 +0200, Kay Sievers wrote:
> On Mon, Jun 7, 2010 at 13:41, Johannes Berg <johannes@sipsolutions.net> wrote:
> > (mind you, I think we probably need to have the bus/driver assignment,
> > but I wanted to try out your suggestion first)
> 
> Class device can never have a driver. And unregistered drivers can
> not be used, what you try to do here. That all should just be removed or
> properly registered with the core if needed.

Yeah but it shouldn't influence the operation? Anyway I see from your
patch that I should have assigned the release function and that would've
helped I guess.

> > So I removed bus/driver assignment from the above code just to try it
> > out, and got
> >
> > Device 'hwsim0' does not have a release() function, it is broken and
> > must be fixed.
> 
> The driver core expects the resources of the device to be freed on
> release. You can provide an empty release function because you do this
> from a global list of devices.

Ok, makes sense.

> > This has evolved far too much for me right now. Can we just apply the
> > initial patch from Eric and be happier for a while? I can't justify
> > spending this much time on it right now. Alternatively, you could look
> > at hwsim too, since it's all virtual, nothing special is required, I do
> > testing in a virtual machine ...
> >
> > current patch is at
> > http://johannes.sipsolutions.net/patches/kernel/all/2010-06-07-11:41/hwsim-bus.patch
> 
> Here is something that seems to work for me.

I see you remove the driver. Does this mean that in sysfs these devices
wouldn't have a driver symlink? ISTR that we needed that for userspace,
but I'm not entirely sure, and I don't have all the relevant userspace
in my test setup.

johannes