Re: [PATCH RFD] alternative kobject release wait mechanism

[Greg KH <greg@kroah.com>]

On Mon, Apr 23, 2007 at 03:40:21PM +0900, Tejun Heo wrote:
> Hello, Dmitry.
> 
> Dmitry Torokhov wrote:
> > Isn't think a good thing? By decoupling the 2 layers we insulate them
> > from changes in each other. This allows bug subsystems to concentrate
> > on topics that important to them instead of worying about refcounting
> > objects that are not directly interesting for the subsystem in
> > question.
> 
> I think the best thing would be make struct device's lifetime rules
> simple enough such that it doesn't really matter to driver subsystems
> and drivers can just do what they wanna do.

I agree.

> Also, separate struct device from the actual implementation has problem
> in that struct device is widely used to refer to the device by many
> layers drivers register devices to.  Basically, you'll have to implement
> immediate-disconnect between struct device and the actual
> implementation.  So, it just shifts the problem from struct device to
> the place between struct device and actual implementation and I think
> struct device itself is better place to deal with that than somewhere
> inbetween it and driver private data.

I also agree.

> > Now for smaller subsystems it may make sense to embed stuct devices
> > into subsystem objects and manage it all together. In fact input
> > system does this but I think it is much simlpier than SCSI or IDE.
> 
> Well, both SCSI and IDE heavily depend on struct device acting as 'base
> class'.  It's all over the place and almost a basic assumption about the
> driver model.

And that's how it should be.

And your sysfs patches now make it a lot easier than before, and I can't
thank you enough for doing that work.

thanks,

greg k-h