[PATCH 2/2] console: sandbox: remove unnecessary sandbox code

[Simon Glass]

Hi Patrick,

On Wed, 2 Dec 2020 at 07:08, Patrick DELAUNAY <patrick.delaunay at st.com> wrote:
>
> Hi Simon,
>
> > From: Simon Glass <sjg at chromium.org>
> > Sent: lundi 30 novembre 2020 21:12
> >
> > Hi Patrick,
> >
> > On Fri, 27 Nov 2020 at 03:49, Patrick Delaunay <patrick.delaunay at st.com>
> > wrote:
> > >
> > > Remove the specific sandbox code in console.c, as the config
> > > CONFIG_DEBUG_UART is already supported in drivers/serial/sandbox.c and
> > > activated by default in all sandbox defconfig
> > > (CONFIG_DEBUG_UART_SANDBOX=y and CONFIG_DEBUG_UART=y).
> > >
> > > This patch allows to test the console code under DEBUG_UART in sandbox
> > > and avoids to include the file <os.h> in this u-boot generic code.
> > >
> > > Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
> > > ---
> > >
> > >  common/console.c | 15 ---------------
> > >  1 file changed, 15 deletions(-)
> >
> > Please see this commit as to why I put that code back, after removing it myself.
> >
> > 64e9b4f346f Revert "sandbox: Drop special case console code for sandbox"
> >
> > Regards,
> > Simon
>
> Thanks to point it, I miss this old commit.
>
> I don't understood the issue in the commit message:
>
>     Revert "sandbox: Drop special case console code for sandbox"
>
>     While sandbox works OK without the special-case code, it does result in
>     console output being stored in the pre-console buffer while sandbox starts
>     up. If there is a crash or a problem then there is no indication of what
>     is going on.
>
>     For ease of debugging it seems better to revert this change also.
>
> the existing code (here for putc, but it is the same for puts)  is:
>
> #ifdef CONFIG_SANDBOX
>         /* sandbox can send characters to stdout before it has a console */
>         if (!(gd->flags & GD_FLG_SERIAL_READY)) {
>                 os_putc(c);
>                 return;
>         }
> #endif
> #ifdef CONFIG_DEBUG_UART
>         /* if we don't have a console yet, use the debug UART */
>         if (!(gd->flags & GD_FLG_SERIAL_READY)) {
>                 printch(c);
>                 return;
>         }
> #endif
>
> For sandbox, when CONFIG_DEBUG_UART is activated
>     printch => _printch => _debug_uart_putc => os_putc
>
> For me these 2 code block are identical for sandbox when CONFIG_DEBUG_UART
>
> And the  issue described is also solved by CONFIG_DEBUG_UART=y
> (consle no use preconsole buffer when serial driver s not ready).
>
> Your concern  is when sandbox is compiled without CONFIG_DEBUG_UART ?
>
> Because it is no more the case with my previous patch (I activate it in sandbox*defconfig)
>
> but to avoid issue in futur (new sandbox*defconfig) it should be better to select (or imply)
> his feature for sandbox  arch in Kconfig and not more activate it in sandbox*defconfig ?
>
> PS: with this sandox code, I don't see how to test the pre console buffer in sandbox...
>        I think that the pre console buffer is alway empty for sandbox
>

OK maybe things have changed. Previously I noticed that the banner did
not output until later. I will take another look.

But I don't want to rely on the debug UART for sandbox to work.

Regards,
Simon