Re: [Qemu-devel] [PATCH 1/3] PPC4xx IIC and MAL

[Hollis Blanchard <hollisb@us.ibm.com>]

On Wed, 2008-12-10 at 14:13 +0000, Salvatore Lionetti wrote:
> Ok
> 
> 1) The line code modified is 80% IIC, only few row about MAL
> 2) MAL until today (if ever this patch enter in qemu) is only used to
> rw registers, so no malfunction is present.
> 3) As you can see many ppc* file are to modify since I2C previous
> support it totally not integrated: have sense modify ppc* and never
> use an IIC device?
> 4) Is error prone and very tedious to extract some code, expecially if
> there is no modularity advantage: one piece require the other,
> 5) I already have successfully tested the expected patch.
> 6) I can't do that directly so every time have 2 see if main line is
> updated or not, merge svn file with current my patch status
> 7) Who apply the patch only apply one click?
> 
> In this moment i have no time to make all this retail and test.

I would be very surprised if somebody applies your patch as-is, because
it's messy (there are a lot of unnecessary/unrelated changes) and it's
very difficult to see the functional changes.

Yes, there is a natural dependency of a patch on the previous ones. This
is called a "patch queue" or "patch series", and you can see other
people submitting them on qemu-devel. (In fact the most recent series
contains 13 patches, with #13 depending on #1-12 being committed
already.)

There are tools (such as quilt, guilt, and MQ) that help you manage
patch series. You can use these tools to maintain your patches and
update them to match the latest qemu tree.

If you submit small independent patches, people will be able to easily
see that they're good and commit them instantly. When you submit a large
patch with lots of changes, it takes a lot more time and effort to
review, and it's much less likely to be accepted.

-- 
Hollis Blanchard
IBM Linux Technology Center