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

[Simon Glass]

Hi Wolfgang,

On Mon, Oct 17, 2011 at 1:25 PM, Simon Glass <sjg at chromium.org> wrote:
> 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.

I took another look at this - in fact this patch has been entirely
superseded by Graeme's:

commit e3e454cd72f319908355427b1a3ae54b3dd53356
Author: Graeme Russ <graeme.russ at gmail.com>
Date:   Mon Aug 29 02:14:05 2011 +0000

    console: Squelch pre-console output in console functions

so there is no need for me to resubmit. The other patch I mentioned,
The board_panic_no_console patch is still of interest though.

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
>>
>