Re: [RFC] bind/unbind uevent

[Sebastian Ott <sebott@linux.vnet.ibm.com>]

On Wed, 8 Dec 2010, Greg KH wrote:
> On Wed, Dec 08, 2010 at 11:18:27AM +0100, Sebastian Ott wrote:
> > On Tue, 7 Dec 2010, Kay Sievers wrote:
> > > On Tue, Dec 7, 2010 at 19:33, Greg KH <gregkh@suse.de> wrote:
> > > > On Tue, Dec 07, 2010 at 06:29:37PM +0100, Sebastian Ott wrote:
> > > 
> > > >> So I'm searching for a trigger when these attributes are created, or
> > > >> in other words when the device is useable, which I think translates to
> > > >> when a driver is bound to this device.
> > > >
> > > > Again, KOBJ_ADD is the correct one.
> > > >
> > > > If your driver is creating sysfs attributes on its own, that's a bug and
> > > > should be fixed.
> > > 
> > > Sounds a bit like the driver should create its own child device with
> > > its own properties, instead of mangling around with attributes at a
> > > device it binds to.
> > 
> > Yes, I get that feeling too. But I'm talking about existing drivers
> > and I don't think I can change their whole structure.
> 
> It's just a matter of putting the attributes in a table and passing that
> to the bus code the driver registers with.  Only a minor change in the
> driver is needed to resolve this.

I don't get it. The current situation is, that our drivers
add attributes to the device they are about to bind with, in
the probe function. I think we agree that it would be better
if those drivers would register a child device and add attributes
to this one. But my concern is that this would break userspace
which walks the sysfs tree and changes attributes, since it changed
from:
/sys/devices/$DEV/$ATTR
to:
/sys/devices/$DEV/$CHILD/$ATTR


> 
> good luck,
> 
> greg k-h
>