[U-Boot] [PATCH v3] powerpc: Restore core of mpc8xx

[Wolfgang Denk]

Dear Christophe,

In message <0784ad6e-86ab-9c1d-1b81-a5cacaf2b01f at c-s.fr> you wrote:
> 
> > Please see my previous comments to Tom's message.  At least, please
> > clean up the directory structure and get rid of unrelated (4xx) and
> > untested/broken code (bedbug, probably kgdb, pcmcia, usb).
> 
> I got 4xx unrelated stuff out in v3, as mentioned above.

I still see these files in your patch:

	drivers/net/4xx_enet.c
	include/configs/CPCI4052.h
	include/configs/MIP405.h
	include/configs/PIP405.h
	include/configs/PLU405.h

To me these look very much like PPC4xx related.  In addition, it
makes zero sense to keep PPC405 board config files without any
related board code.

On the other hand I do not see a single board configuration for 8xx,
so you cannot even compile the code for a MPC8xx board, or am I
missing something?



> > Also, are you going to support the whole family, including MPC823(E)?
> > If not, we should also omit stuff like the 823 video support.
> 
> I agree, but please no big-bang now. It is already complicated enough.

I try to get used to the idea of doing code level cleanup later,
even though my personal feeling for re-adding known-to-be-broken
code is not exactly positive.


But at least at file level we should perform the needed cleanup now:
- omit unrelated stuff
- omit known to be unsupported/untested/broken code
- move drivers to the correct places according to today's file
  system hierarchy.

As I explained before, I doubt that you will be able to test things
like  drivers/video/mpc8xx_lcd.c  on your boards, and I strongly
doubt that you are willing to invest efforts in adapting and testing
things like PCMCIA, bedbug, SIL680 support, or USB on your hardware.

[In which way is the sil680 driver related to mpx8xx, btw?]


So when we know in advance that this old, crappy code will never be
tested, why should we spend effforts even in adding it?

> We have something that fits and that was unexpectedly removed entirely 
> last week. Lets come back first to a well known - working situation and 
> do the removal of unnecessary parts step by step as if we were 3 weeks 
> ago. The more we wait to get 8xx back in, the more difficult it will be.

To be frank: you don't have a very extensive track record of working
with the U-Boot community.  At the moment all we have is your claim
that you will care about 8xx in the furture.  In the past, we have
seen many precedents of "please add this code now, I know it is not
really good, but I will fix it later, promised" - and then the code
was in mainline, until somebody else digged into cleaning it up.


I've been using MPC8xx for 18 years, and I know all too well in how
many places the code is in urgent need of a cleanup (heck, I'm even
responsible for major parts of that mess - but those were the times
way back then).  I'm not sure if you already anticipate the size of
job you have taken.  Just looking at the POST code - are you aware
how much effort it will be to adapt it to your board and to test it?
And this is mandatory requirement if you want to have it added. It
must be maintained, i. e. tested.

It would be very sad if we add this code now, and in a few
weeks/months you say: oh, we don't need this, and I don't find time
to care about it, let's remove it again.  And this is what's bound
to happen - I bet a beer or two that you have never used most of
this code before, nor had a look at the code.


I think it is much, much better to perform at least the file level
cleanup in a sngle step right at the beginning, starting with the
minimum set of needed files for your system.  Adding needed things
later is a much better guaranteee for good code than removing
unmaintained crap when it starts hurting.


So please check your own board configuration and come up with a list
of needed features, and re-add only those, cleaning up file
hierarchy while you go.  See .sig below (non-random today).

Thanks.

Best regards,

Wolfgang Denk

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