[U-Boot] [PATCH] tegra: Specify debugging serial port at boot.

Simon Glass sjg at chromium.org
Thu Mar 22 16:17:50 CET 2012


Hi Wolfgang,

On Thu, Mar 22, 2012 at 6:25 AM, Wolfgang Denk <wd at denx.de> wrote:
> Dear Simon Glass,
>
> In message <CAPnjgZ1u8paSeKxozWz1D5YoJaJ2um_q0dWQo=k5_+HEdKh1AQ at mail.gmail.com> you wrote:
>>
>> >> OK, so revert that commit?
>> >
>> > It hasn't hit mainline yet, or has it?
>>
>> Yes, it is there, sorry.
>
> Which commit is that?

It was 295d3942: Add board_pre_console_putc to deal with early console output

The discussion threads are around here:

http://lists.denx.de/pipermail/u-boot/2011-August/099620.html


If you are looking for a revert :-)

http://patchwork.ozlabs.org/patch/147617/

>
>> > This is why initializing the serial console has always been one of the
>> > very, very first initialization steps in U-Boot.
>>
>> So if actually you want a pre-console panic() to be silent then that's fine.
>
> I do not _want_ it.
>
> This is a simple matter of facts that cannot be avoided.  If we cannot
> initialize the consolem then we cannot print anything.
>
>> It's a little unfriendly though - so would you be interested in
>> keeping board_pre_console_putc() around if we could solve this
>> entirely with code in there? It turns out that Tegra has a setting for
>> console UART in the hardware parameters that we can access.( I won't
>> ask you about how to handle a panic() in SPL yet).
>
> If you can initialize the console in a way that allows sending
> characters, then just do this - do this as part of the recular
> fconsole init code, so we do have a working console, and we do not
> need ay "pre-console" stuff.
>

OK, let's leave it for now, I don't see a way of achieving this in the
case of an early panic.

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
> It is common sense to take a method and try it. If it fails, admit it
> frankly and try another. But above all, try something.
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