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

[Heinrich Schuchardt]

On 9/22/20 8:48 PM, Simon Glass wrote:
> 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?

Are you worried about relocation?

The initialization of the global data fields should be done in
log_init() before gd->flags |= GD_FLG_LOG_READY; I assume.

Is the rest ok for you?

Best regards

Heinrich

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