[U-Boot] [PATCH 2/2] Add check that console is ready before output

[Simon Glass]

Hi Wolfgang,

On Mon, Oct 17, 2011 at 1:11 PM, Wolfgang Denk <wd at denx.de> wrote:
> Dear Simon Glass,
>
> In message <1314633910-8550-3-git-send-email-sjg at chromium.org> you wrote:
>> If puts() or printf() is called before the console is ready, U-Boot will
>> either hang or die. This adds a check for this so that debug() can be used
>> in early code without concern that it will hang.
>>
>> U-Boot boots properly
>>
>> Tested-by: Simon Glass <sjg at chromium.org>
>> Signed-off-by: Simon Glass <sjg at chromium.org>
>> ---
>>  common/console.c |    4 ++--
>>  1 files changed, 2 insertions(+), 2 deletions(-)
>
> Isn't this just hushing up implementation errors?
>
> Before, the incorrect call would cause U-Boot to fail - a situation
> which cannot be overlooked during the port, so the problem will
> quickly be analyzed and fixed.
>
> With your commit, everything appears to work fine, just some
> (expected) output will be missing.  This is misleading at beats, and
> will cause that buggy code will go undetected for a long time.
>
> I don't think this is a good strategy.
>
> Please comment.

Yes indeed -  I did actually submit an 'early panic' patch which I
should take another look at - it is called 'Add board_panic_no_console
to deal with early critical errors'. I think it was in the same patch
set but I'm not sure.

It would panic when console output was performed before the console
was ready - and therefore give the behaviour you desire.

Regards,
Simon

>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
> Compassion -- that's the one things no machine ever had.  Maybe it's
> the one thing that keeps men ahead of them.
>        -- McCoy, "The Ultimate Computer", stardate 4731.3
>