[PATCH] Define default CONFIG_PREBOOT with right config option

[Patrick DELAUNAY]

Hi,

> From: U-Boot <u-boot-bounces at lists.denx.de> On Behalf Of Peter Robinson
> Sent: mardi 29 septembre 2020 11:48
> 
> The 44758771ee commit removes CONFIG_PREBOOT but actually sets the
> USE_PREBOOT Kconfig option which isn't CONFIG_PREBOOT and is also a bool
> option which means we regress because 'usb start' isn't run when expected, it
> should also be run for devices that have USB storage because keyboards aren't
> the only thing we might need the USB bus for.
> 
> Fixes: 44758771ee ("arm: move CONFIG_PREBOOT="usb start" to KConfig")
> Signed-off-by: Peter Robinson <pbrobinson at gmail.com>
> Cc: Jonas Smedegaard <dr at jones.dk>
> Cc: Neil Armstrong <narmstrong at baylibre.com>
> ---
>  common/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/common/Kconfig b/common/Kconfig index b1934b3a9c..9c20a9738e
> 100644
> --- a/common/Kconfig
> +++ b/common/Kconfig
> @@ -403,7 +403,6 @@ config BOOTCOMMAND
> 
>  config USE_PREBOOT
>  	bool "Enable preboot"
> -	default "usb start" if USB_KEYBOARD
>  	help
>  	  When this option is enabled, the existence of the environment
>  	  variable "preboot" will be checked immediately before starting the @@ -
> 417,6 +416,7 @@ config USE_PREBOOT  config PREBOOT
>  	string "preboot default value"
>  	depends on USE_PREBOOT && !USE_DEFAULT_ENV_FILE
> +	default "usb start" if USB_KEYBOARD || USB_STORAGE
>  	default ""
>  	help
>  	  This is the default of "preboot" environment variable.
> --
> 2.26.2

For information, this patch cause unexpected 'usb start' on STM32MP15x boards
and slow down the start-up in realease v2020.10.

For me it is unexpected because
- USB keyboard is not activated
- USB storage is activated but USB boot is not supported (not managed by distro boot command)

I sent a patch [1] for the associated defconfig but I'm afraid that other boards are impacted.

As the USB storage boot initialization is correctly managed by distro boot command 'usb_boot' 
(defined in include/config_distro_bootcmd.h, it already include 'usb start'), I think that the 
USB_STORAGE test should be removed or limited by !DISTRO_DEFAULTS.

[1] = "configs: stm32mp: force empty PREBOOT"
http://patchwork.ozlabs.org/project/uboot/patch/20201007081020.30635-1-patrick.delaunay@st.com/

Regards

Patrick