Re: [PATCH v2] printk: Document that CONFIG_BOOT_PRINTK_DELAY required for boot_delay=

[Randy Dunlap]

On 1/26/23 14:54, Bjorn Helgaas wrote:
> From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> 
> Document the fact that CONFIG_BOOT_PRINTK_DELAY must be enabled for the
> "boot_delay" kernel parameter to work.  Also mention that "lpj=" may be
> necessary.
> 
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>

Reviewed-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

Thanks.

> ---
> Changes from v1 (https://lore.kernel.org/all/20230123180440.901793-1-helgaas@xxxxxxxxxx/):
> - Clarify use of "lpj=".  Reword consequences of delay larger than 10000.
> 
>  Documentation/admin-guide/kernel-parameters.txt | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 6cfa6e3996cf..814e58487239 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -480,8 +480,10 @@
>  			See Documentation/block/cmdline-partition.rst
>  
>  	boot_delay=	Milliseconds to delay each printk during boot.
> -			Values larger than 10 seconds (10000) are changed to
> -			no delay (0).
> +			Only works if CONFIG_BOOT_PRINTK_DELAY is enabled,
> +			and you may also have to specify "lpj=".  Boot_delay
> +			values larger than 10 seconds (10000) are assumed
> +			erroneous and ignored.
>  			Format: integer
>  
>  	bootconfig	[KNL]

-- 
~Randy