[U-Boot] [PATCH] include/ns16550.h: Unify structure declaration for registers

[Wolfgang Denk]

Dear Detlev,

In message <m2zldsanbe.fsf at ohwell.denx.de> you wrote:
> 
> >> to be "simpler and more solid" readb(struct->field) (which is
> >> effectively what we have in the current implementation)?  You consider
> >> "more configurable" to be a good in its own?
> >
> > Yes.
> 
> Wow.  As a rhetorical question - where do you actually draw the line if
> you consider configurable to be a good in its own?  Shouldn't we then

This is actually an easy question.

We draw the line such that

1) all boards that are supported in the mainline code continue to work
   at least not worse than they did before.
and
2) reasonable hardware configurations that can be foreseen are either
   supported out of the box or can be added with only little effort
   (i. e. without effort that is close to a redesign).

In the current situation, we have an out-of-tree port *plus* a
hardware design that can be considered broken.

Both are very good reasons not to spend special efforts to support
such a board.


> have configuration options for UARTs who are attached bit-reversed on
> the databus also?  And an option for a bit-shift in the data itself?

No, of course not.


> > I admit the address decoder in my UART hardware is weird and needs
> > special configuration,  but this is not just for my case, it's not
> > unusual.

Well, here I disagree with Shinya Kuribayashi - the fact that we don't
have *any* board with such requirements in mainline, and that it never
popped up before, is pretty clear proof that such a configuration is
highly unusual (or, with less diplomatic words, broken).

> > There're various kind of hardwares in the world, and there're many
> > U-Boot ports which can not be pushed to upstream for various reasons.

I can not imagine any reasons why a U-Boot port could not be pushed
upstream. It's GPL software after all...

> > We can easily ignore such boards of course, but it would be very nice
> > for U-Boot if it could provide easy configurable drivers and could
> > support as many hardwares as possible.
> 
> Currently it seems that all in-tree boards can be accomodated with the
> construct that I suggested.  I am not at all sure that we want code
> which is only used by out-of-tree ports.
> 
> Post the port and we can rediscuss new code.

Full ACK here.  It makes no sense to spend time and resources on sup-
porting out-of-tree ports on broken hardware.

Best regards,

Wolfgang Denk

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