Subject: Re: [Bugme-new] [Bug 16257] New: sysfs changes break hwsim and bnep drivers

From: [email-masked] (Eric W. Biederman)
Date: Mon, 21 Jun 2010 17:05:21 -0700

Greg KH <[email-masked]> writes:

> On Mon, Jun 21, 2010 at 03:55:35PM -0700, Eric W. Biederman wrote:
>> Greg KH <[email-masked]> writes:
>> 
>> > I _really_ do not like this patch.
>> >
>> > The correct thing is to fix the modules that are affected, and that's
>> > only the wireless testing module, right?  Or is there something else?
>> >
>> > And if that code is properly converted to a bus, what needs to change in
>> > the driver core?
>> 
>> The usb bnep driver.
>
> Odd, what is bnep doing differently here from all other network drivers?
> Is it trying to stack the bluetooth class in the middle somehow?
> Shouldn't this be easy to fix up in the driver itself?

The cause of all of the failures is a class device with a class device
parent, instead of a bus device parent.  Which causes the net/ directory 
not to be created for us to put the network devices under.

I don't have a clue about how that driver works, and I don't know how many
other drivers that do something strange like this are out there lurking.

I have not been involved previously in any changes from class device to
bus device so I don't have a clue how difficult it would.  All I know
is that with the mac80211_hwsim driver we had first had two people who
really knew what they were doing and it was hard enough there still
isn't a working conversion away from class devices.

Eric