[U-Boot] [PATCH 4/4] powerpc: Add LINK_OFF calls in early C-code.

[Wolfgang Denk]

Dear Joakim Tjernlund,

In message <OF287114D8.013B6E51-ONC125781C.00667DCD-C125781C.00673260 at transmode.se> you wrote:
>
> > You don't need to make the MMU trick work on all boards, just your board
> > (or cpu family), because it wouldn't be imposing anything on
> > the rest of the system.  Do we actually have someone who
> > needs this feature on a board without a suitable MMU, large lockable
> > cache or other SRAM, hardware bank switching, or other mechanism
> > that can be confined to early low-level board/cpu-specific code?
> 
> Wolfgang seems to think so. As I read his reply he wants a solution for all

Please be aware that I don't think anything at all.  I just comment :-)

I'm not in your position, where I am focussing on "how can I implement
this".  I'm looking at the code from the outside, and I ask what does
it give to me, what of the things I'd like to have does it not give to
me, and at which price does it come.

> boards which I don't think is possible. I do think my approach comes closest though.
> I did try BATs but I didn't get very far.

If we are talking about _all_ boards we have to keep a wider view.
For example, on MPC8xx there are not BATs. Not to mention other
architectures.


Actually I was not asking for support for all boards, not even for
all boards of a specific architecture, or a specific CPU.  You
submitted this patch, and I learned that the code, as is, is only
useful for a single board, which appears to be maintained in an
out-of-tree port.  For all in-tree boards the code, as is, is broken
and unusable without further rework.  Needless to repeat that it is
completely untested for mainline.

So we have a patch that promises a feature, which cannot be used by
any of the mainline boards, but it makes the code more complex for
zero benefit.

It's a nice and appreciated RFC patch or even example implementation,
but I fail to see arguments why we should add this to mainline.

Best regards,

Wolfgang Denk

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