[PATCH 1/2] log: allow for message continuation

[Simon Glass]

Hi Heinrich,

On Thu, 17 Sep 2020 at 06:19, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> Some drivers use macro pr_cont() for continuing a message sent via printk.
> Hence if we want to convert printk messaging to using the logging system,
> we must support continuation of log messages too.
>
> As pr_cont() does not provide a message level we need a means of
> remembering the last log level.
>
> With the patch a pseudo log level LOGL_CONT as well as a pseudo log
> category LOGC_CONT are introduced. Using these results in the application
> of the same log level and category as in the previous log message.
>
> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> ---
>  common/log.c            | 23 ++++++++++++++++++-----
>  doc/develop/logging.rst |  6 ++++++
>  include/log.h           |  2 ++
>  3 files changed, 26 insertions(+), 5 deletions(-)
>
> diff --git a/common/log.c b/common/log.c
> index 9a5f100da3..bafc09f263 100644
> --- a/common/log.c
> +++ b/common/log.c
> @@ -183,10 +183,12 @@ static bool log_passes_filters(struct log_device *ldev, struct log_rec *rec)
>   * log_dispatch() - Send a log record to all log devices for processing
>   *
>   * The log record is sent to each log device in turn, skipping those which have
> - * filters which block the record
> + * filters which block the record.
>   *
> - * @rec: Log record to dispatch
> - * @return 0 (meaning success)
> + * All log messages created while processing log record @rec are ignored.
> + *
> + * @rec:       log record to dispatch
> + * Return:     0 msg sent, 1 msg not sent while already dispatching another msg
>   */
>  static int log_dispatch(struct log_rec *rec)
>  {
> @@ -199,7 +201,7 @@ static int log_dispatch(struct log_rec *rec)
>          * as this might result in infinite recursion.
>          */
>         if (processing_msg)
> -               return 0;
> +               return 1;
>
>         /* Emit message */
>         processing_msg = 1;
> @@ -214,10 +216,18 @@ static int log_dispatch(struct log_rec *rec)
>  int _log(enum log_category_t cat, enum log_level_t level, const char *file,
>          int line, const char *func, const char *fmt, ...)
>  {
> +       static enum log_category_t logc_prev = LOGC_NONE;
> +       static enum log_level_t logl_prev = LOGL_INFO;

I don't think we can use static variables in logging. Perhaps we can
use gobal_data?


>         char buf[CONFIG_SYS_CBSIZE];
>         struct log_rec rec;
>         va_list args;
>
> +       /* Check for message continuation */
> +       if (cat == LOGC_CONT)

Regards,
Simon