Re: [PATCH 0/3] ARM: dts: stm32: lxa: change stdout-path baud rate from 9600 to 115200

[David Laight]

On Thu, 11 Jun 2026 20:12:32 +0200
Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> wrote:

> The LXA boards are the only STM32 boards that set stdout-path = &uart*
> instead of explicitly specifying a baud rate.
> 
> This would mean the default of 9600 is used, but it goes unnoticed when
> booting normally as barebox fixes up a console= line that includes a
> baud rate.
> 
> When EFI booting GRUB however, GRUB will not pass along the console=
> line and thus the board ends up with a 9600 baud Linux console,
> confusing users.

Is it possible to determine the current baud rate (by reading the hardware
register) and default to that value.
Then if grub has initialised the uart the kernel will use the same
baud rate.

	David

> 
> This series fixes this. As the device trees were added at different
> times, they are fixed each in a separate commit with its own Fixes: tag.
> 
> ---
> Ahmad Fatoum (3):
>       ARM: dts: stm32: lxa-mc1: change stdout-path baud rate from 9600 to 115200
>       ARM: dts: stm32: lxa-tac: change stdout-path baud rate from 9600 to 115200
>       ARM: dts: stm32: fairytux2: change stdout-path baud rate from 9600 to 115200
> 
>  arch/arm/boot/dts/st/stm32mp153c-lxa-fairytux2.dtsi | 2 +-
>  arch/arm/boot/dts/st/stm32mp157c-lxa-mc1.dts        | 2 +-
>  arch/arm/boot/dts/st/stm32mp15xc-lxa-tac.dtsi       | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> ---
> base-commit: 4549871118cf616eecdd2d939f78e3b9e1dddc48
> change-id: 20260611-lxa-stdout-path-baudrate-7cf454cdae07
> 
> Best regards,
> --  
> Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> 
>