Re: [Qemu-devel] [PATCH 1/5] hw/char: remove console_exit function in sclp

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

On Thu, 27 Apr 2017 20:23:51 +0800
Zihan Yang <tgnyang@gmail.com> wrote:

> OK, sorry for the confusion, I will give a new patch series. I'm not very
> familiar with
> the conventions so I wonder if someone could help clarify some principles
> for me.
> I'd like to replace all the init/exit callback of DeviceClass to
> realize/unrealize,  and
> convert return type of exit callback of some higher-level classes, like
> HDACodecDeviceClass, to void.
> 
> My first question Is it a good idea to split these patches into two series?
> For example,
> one series to convert exit callback of these higher-level classes to void,
> and then the
> other to replace all the init/exit callback of DeviceClass to
> realize/unrealize.

This is probably a good idea: converting exit callbacks to void is
relatively straightforward, while converting to realize/unrealize might
be better done while revisiting some of the modelling of the relevant
subsystems. (For example, all classes for virtio-ccw use the same exit
callback - it might be a good idea to do the same work in a common
unrealize function when you touch it anyway.)

> 
> The second question is that should I always give separate patch for
> different directories?
> One  example is that in both hw/ide and hw/block, I need to replace the
> init callback with
> realize in some high-level classes, should I give two patches or just give
> one patch for
> the work?

A better way to split is along maintainership responsibilites (which
may or may not align with directories). Again, sticking with the code I
maintain, I would merge changes to hw/char/sclp* and hw/s390x/, but not
to other code in hw/char/. Try to stick to logical units (continuing
with that example, different patches for sclp and virtio-ccw would make
sense).

The most important thing to remember when splitting changes is that you
need to preserve bisectability, i.e. every step in your patch series
needs to compile.