[PATCH] dmesg: restrict output to default log level by default

[Sascha Hauer]

On Thu, Jan 16, 2025 at 03:07:52PM +0100, Ahmad Fatoum wrote:
> When loglevel is set to debug, dmesg shows a torrent of messages,
> because by default it shows all messages logged regardless of the
> default log level.
> 
> To make it more convenient to use, change this to only print the same
> messages that are synchronously printed by default.
> 
> Users wanting to see more can specify a log level via an extra argument
> to the dmesg command.

The default behaviour of the Linux command is to display all messages. I
would prefer the same behaviour for the barebox command. I think it's too
easy to forget that we could get more information by passing -l.

Also with this patch applied there is no easy way to restore the current
behaviour (unless CONFIG_DEFAULT_LOGLEVEL is 8 already). You would have
to do a

dmesg -l vdebug,debug,info,notice,warn,err,crit,alert,emerg

(I wonder why at least the Linux command doesn't support passing "all"
or "info+" as loglevel string)

Sascha

> 
> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
> ---
>  commands/dmesg.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/commands/dmesg.c b/commands/dmesg.c
> index 8a60f075076e..99675b6c2804 100644
> --- a/commands/dmesg.c
> +++ b/commands/dmesg.c
> @@ -78,7 +78,7 @@ static int do_dmesg(int argc, char *argv[])
>  {
>  	int opt, ret, i;
>  	int delete_buf = 0, emit = 0;
> -	unsigned flags = 0, levels = 0;
> +	unsigned flags = 0, levels = GENMASK(CONFIG_DEFAULT_LOGLEVEL, 0);
>  	char *set = NULL;
>  
>  	while ((opt = getopt(argc, argv, "ctderl:n:")) > 0) {
> -- 
> 2.39.5
> 
> 
> 

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