[PATCH v2 4/9] log: use console puts to output trace before LOG init

[Sean Anderson]

On 11/27/20 5:20 AM, Patrick Delaunay wrote:
> Use the console puts functions to output the traces before
> the log initialization (when CONFIG_LOG is not activated).
> 
> This patch allows to display the first U-Boot traces
> (with macro debug) when CONFIG_DEBUG_UART is activated
> and not only drop them.
> 
> For example for traces in board_f.c requested by the macro debug,
> when LOG_DEBUG is defined and CONFIG_LOG is activated.
> 
> Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
> ---
> 
> Changes in v2:
> - replace printascii by console puts, remove test on CONFIG_DEBUG_UART
> 
>   common/log.c | 9 +++++++++
>   1 file changed, 9 insertions(+)
> 
> diff --git a/common/log.c b/common/log.c
> index 212789d6b3..a4ed7d79f8 100644
> --- a/common/log.c
> +++ b/common/log.c
> @@ -246,6 +246,15 @@ int _log(enum log_category_t cat, enum log_level_t level, const char *file,
>   
>   	if (!(gd->flags & GD_FLG_LOG_READY)) {
>   		gd->log_drop_count++;
> +
> +		/* display dropped traces with console puts and DEBUG_UART */
> +		if (rec.level <= CONFIG_LOG_DEFAULT_LEVEL || rec.force_debug) {
> +			va_start(args, fmt);
> +			vsnprintf(buf, sizeof(buf), fmt, args);
> +			puts(buf);
> +			va_end(args);
> +		}
> +
>   		return -ENOSYS;
>   	}
>   	va_start(args, fmt);
> 

Couldn't this be done like

  	va_start(args, fmt);
  	vsnprintf(buf, sizeof(buf), fmt, args);
  	va_end(args);
  	rec.msg = buf;
	if (!gd || !(gd->flags & GD_FLG_LOG_READY)) {
		if (gd)
			gd->log_drop_count++;
		if (rec.level < CONFIG_LOG_DEFAULT_LEVEL ||
		    rec.force_debug)
			puts(buf);
		return -ENOSYS;
	}

I don't see the optimization of not doing the vsnprintf() coming up very
often. Also, shouldn't this return 0 instead of ENOSYS if something is
actually printed?

--Sean