Re: [PATCH] pci: separate out pci_add_dynid()

From: Greg KH
Date: Wed Sep 02 2009 - 20:10:56 EST

On Thu, Sep 03, 2009 at 07:43:28AM +0900, Tejun Heo wrote:
> Ummm... another thought.
> Tejun Heo wrote:
> > It's one of the gripes I've had with the driver core interface.
> > Returning the object which had its reference bumped up is nice to do
> > do_something(get_driver(driver)); but it should have been made clear
> > that the return value always equals the input parameter. IIRC, in the
> > early days of the current driver model and kref, there were intentions
> > to make kref somehow more capable and handle the last reference
> > problem from within it so that if (get_driver(driver)) test is
> > actually meaningful but that turned out to be not too feasible, so we
> > ended up with unnecessary if () around driver model get functions. I
> > try to remove them whenever an affected piece of code is being
> > modified but there still are plenty left. I'll update comment on
> > driver core get functions.
> Greg, I think I suggested this before. What do you think about just
> making those get functions return void?

I have no objection to that at all.

> The current interface combined with widespread if() around them is
> quite misleading.

I agree.

> Most device/driver structures are inherited and extended when actually
> in use, so the driver or its subsystem code usually can't do much with
> the return value other than checking for bogus error condition anyway.

I totally agree.


greg k-h
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