Re: [RFC] bind/unbind uevent

[Cornelia Huck <cornelia.huck@de.ibm.com>]

On Tue, 14 Dec 2010 11:29:52 -0800,
Greg KH <gregkh@suse.de> wrote:

> On Tue, Dec 14, 2010 at 07:26:40PM +0100, Sebastian Ott wrote:
> > 
> > On Mon, 13 Dec 2010, Greg KH wrote:
> > > On Mon, Dec 13, 2010 at 08:27:45PM +0100, Sebastian Ott wrote:

> > > Don't do that, have your _driver_ register the attributes with the bus
> > > it is on, then when the binding happens, the attributes will
> > > automatically get created for the device before the notification is sent
> > > to userspace.  That is the proper proceedure here.
> > 
> > are you suggesting that these driver specific device attributes should be
> > created by the bus code which registers the device?
> 
> Yes.
> 
> > at this time it is not determinable which driver will bind to the device
> > (and therefore which attributes to create), also driver specific data may 
> > not be initialized.
> 
> {sigh}
> 
> Please go _look_ at how the driver model handles this type of thing.  It
> does _exactly_ what you want, as we have been doing it for _years_
> properly.
> 

I don't understand how this could work. All of the attribute (groups)
registered before the uevent are driver-ignorant. If the bus wants to
specify the attributes, it needs to know the driver the device will
bind to (regardless of whatever tables exist that show the driver <->
attribute relationship). But it cannot know the driver until after the
uevent. Or else it would need to create _all_ attributes for _all_
devices (surely you didn't mean that)? And what happens with drivers
that are loaded later on?

Could you please elaborate on how the attributes could be created in a
compatible way with today's driver core?

Cornelia