[U-Boot] [PATCH] LCD: Add an option to skip registration as an stdio output

[Ayotte, Stephane]

On December-02-15 12:30 AM, Hannes Schmelzer wrote:

> On 12/01/2015 10:31 PM, Ayotte, Stephane wrote:
>
> Hi Stephane,
> > Thanks for the info, Hannes. I agree with you that I could have met my
> requirements (of showing  "applicative" output to the LCD and
> "technical/debug" output to the serial port) with
> CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE. To be totally honest, I had not
> seen this config and was attracted to how the video device did it.
> >
> > For the sake of argumentation only, I will raise the question whether
> CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE breaks NETCONSOLE. If I
> understand correctly, this config will force the console to use only the serial
> device. I could imagine use cases for netconsole and LCD.
> >
> > I'm asking the question, really, as this is just from my reading of the code. I
> haven't tested with netconsole.
> I also read the code again and my understanding is.
> First the environment is asked for stdin, stdout, stderr devices - afterwards
> overwrite_console is asked how about searching for some other devices.
> If overwrite_console returns != 0 the devs inputdev,outputdev,errdev are left
> uninitialized / values from environment (see line 802...805 in
> common/console.c).
>
> A few lines afterwards the fallback takes care about if NULL and assigns "serial"
> to them.
>
> So there is no indication for me breaking netconsole.
> Further i'm also using netconsole on my B&R boards, its working fine.

Thanks for the clarification. In that case, you are right that we end up with two different solutions.
It's too bad your clarification came just a little after the pull request.

> > My feeling is that there should be a more generic way of saying whether a
> device should register to stdio or not. My preference would go to an API over
> individual configs for each device. Neither of the two solutions are ideal nor
> completely implemented as this time.
> >
> > Anatolij, based on Hannes info, if you want to backtrack on this, I'm open both
> ways.
> I would suggest to have not too much ways for one goal. Maybe it would be
> enough work a bit on documentation how to quiet console on LCD.

I agree with you 100% on not having multiple ways. What would be the procedure at this point?
Submit a reverse patch?

Regards,
Stephane

> > Thanks,
> > Stephane
> best regards,
> Hannes
> > ________________________________________
> > From: U-Boot [u-boot-bounces at lists.denx.de] on behalf of Hannes
> > Schmelzer [hannes at schmelzer.or.at]
> > Sent: Tuesday, December 01, 2015 12:41 PM
> > To: Anatolij Gustschin; sayotte.tyco at gmail.com
> > Cc: u-boot at lists.denx.de; trini at konsulko.com
> > Subject: Re: [U-Boot] [PATCH] LCD: Add an option to skip registration
> > as an stdio output
> >
> > hi,
> >
> > sorry i was absent a few days from u-boot (writing vxWorks drivers :-() ...
> >
> > but, do we really need this ?
> >
> > i had same problem on my b&r boards, were we printout something on lcd
> > but console should remain on stdout/stdin.
> >
> > what about:
> >
> > int overwrite_console(void)
> > {
> >       return 1;
> > }
> >
> > and activate
> > #define CONFIG_SYS_CONSOLE_IS_IN_ENV
> > #define CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
> >
> > should do the same i think.
> >
> > best regards,
> > Hannes
> >


________________________________

This e-mail contains privileged and confidential information intended for the use of the addressees named above. If you are not the intended recipient of this e-mail, you are hereby notified that you must not disseminate, copy or take any action in respect of any information contained in it. If you have received this e-mail in error, please notify the sender immediately by e-mail and immediately destroy this e-mail and its attachments.