[U-Boot] The post_list array order change

[Michael Zaidman]

On Mon, Feb 15, 2010 at 11:30 AM, Detlev Zundel <dzu at denx.de> wrote:
> Hi Michael,
>
>> In continuation to my post where I explained necessity
>> of user defined post_progress_status facility
>> (see. http://lists.denx.de/pipermail/u-boot/2010-February/067662.html)
>> I am looking now for the best way of causing the diagnostics output
>> interface test to be run first. In my case it is the diagnostics LEDs test.
>
> Just out of interest, what exactly do you test there?  Do you have any
> way of measuring if the LEDs work or not?

The test blinks the LEDs few times and performs running “1” ilumination.
Of course only visual control is possible. The general idea behind adding
simplest user interface (what the GPIO LEDs are pretended to be) is to
supply earlier possible indication about board status in the cases where
board was stuck before serial console is available or in the field where
there is not the serial console at all. For this reason it makes sense to
validate sanity of this interface as soon as possible.

>
>> I would like to ask which one of the possibilities is preferable:
>> add the “diagout” test to the head of the post_list array or
>> override the post_list with proprietary one and make changes
>> in the board specific file.
>> Please comment.
>
> As always, I would try to keep as much in common code as possible, so
> I'd vote to prepend the entry in the global variable.  After all, it
> will be CONFIG_SYS_POST_DIAG protected, correct?
>
> But then again, the order of the tests should generally be from the
> simple to the more complex, so I would really need to know what your
> test does.  I.e. will a failure in the test be a general POST failure?
> Can it run if already available tests will fail?

I supposed that running from the ROM and performing GPIO writes are
relatively simple things.

The test is not “show stopper case” as far as there is at least one available
user interface channel to deliver test’s reports.

>
> Actually, looking at the current order, it is not very clear to me if
> this is "optimal" in the light of the thoughts laid out in the previous
> paragraph.
>
> It seems I have to think about this a little more.  Does anybody else
> have an idea if the current ordering is in any way sensible?

Alternatively, this kind of testing can be done outside of the POST framework.
Probably, the better place is the board_early_init_f?

>
> Cheers
>  Detlev
>
> --
> I think that level of generalization is too abstract for useful thinking.
>             -- Richard Stallman in <E19N344-0006Q9-Bt at fencepost.gnu.org>
> --
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