Re: Documentation for sysfs, hotplug, and firmware loading.

[Greg KH <greg@kroah.com>]

On Fri, Jul 20, 2007 at 09:54:01AM +0200, Cornelia Huck wrote:
> On Fri, 20 Jul 2007 00:00:01 -0700,
> Greg KH <greg@kroah.com> wrote:
> 
> > > I don't insist on it, mknod insists on it.  You cannot mknod a dev node 
> > > without specifying block or char.
> > > 
> > > You're saying that sysfs should provide major and minor numbers without 
> > > anywhere specifying "char" or "block", meaning the major and minor numbers 
> > > cannot be _used_.  I am insisting on getting the third piece of information 
> > > without which "major" and "minor" are useless.
> > > 
> > > I asked very specifically about this at OLS, several times.  What you're 
> > > telling me now seems to contradict what you told me then.
> > 
> > Here's the rule:
> > 	If the SUBSYSTEM is "block", it's a block device.  Otherwise
> > 	it's a char device.
> 
> That's actually quite confusing to the casual reader, since:
> 
> > But also realize that the majority of events you will get have nothing
> > to do with device nodes.  I think you are forgetting this fact.
> 
> So the rule should be:
> 	If the SUBSYSTEM is "block" (implying major/minor are provided),
> 	it's a block device.
> 	If the SUBSYSTEM is not "block", and major/minor are provided,
> 	it's a char device.
> 	If major/minor are not provided, the event/device is not
> 	relevant to device node creation.

Yes, that is much more descriptive, thanks.

greg k-h