[U-Boot] [PATCH] env: ti: boot: Use ttyS2 instead of ttyO2

[Sam Protsenko]

+ Dan Rue

On Tue, Jul 9, 2019 at 5:49 PM Sam Protsenko <semen.protsenko at linaro.org> wrote:
>
> ttyO2 console enables legacy CONFIG_SERIAL_OMAP driver in kernel.
> Nowadays it's preferred to use the generic CONFIG_SERIAL_8250_OMAP
> driver, which being enabled via ttyS2 console. Both drivers are enabled
> in multi_v7_defconfig and in omap2plus_defconfig, for compatibility
> reasons. Let's switch to ttyS2 console, to be sure that standard 8250
> serial driver is used.
>
> Similar behavior can be also achieved by enabling
> CONFIG_SERIAL_8250_OMAP_TTYO_FIXUP option in kernel, but it's better not
> to rely on that, as it can be disabled or removed after transitional
> period.
>
> Right now on DRA7/AM57x platforms the 8250-omap driver is being probed
> first, and omap-serial driver is only probed if the first one failed.
> It can be seen from uart3 definition in arch/arm/boot/dts/dra7-l4.dtsi:
>
>     compatible = "ti,dra742-uart", "ti,omap4-uart";
>
> So the kernel already uses 8250 driver. This change basically allows
> kernel developers to throw away the omap-serial driver and associated
> compatibility options. Similar discussions [1,2] have started several
> years ago, so it should be safe to do that now.
>
> [1] https://patchwork.kernel.org/patch/6198471/
> [2] http://processors.wiki.ti.com/index.php/Sitara_Linux_UART_-_Switching_to_8250_Driver
>
> Signed-off-by: Sam Protsenko <semen.protsenko at linaro.org>
> ---
>  include/environment/ti/boot.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/environment/ti/boot.h b/include/environment/ti/boot.h
> index e37004af46..d69ba3a7a6 100644
> --- a/include/environment/ti/boot.h
> +++ b/include/environment/ti/boot.h
> @@ -10,7 +10,7 @@
>  #define __TI_BOOT_H
>
>  #ifndef CONSOLEDEV
> -#define CONSOLEDEV "ttyO2"
> +#define CONSOLEDEV "ttyS2"
>  #endif
>
>  #define VBMETA_PART_SIZE               (64 * 1024)
> --
> 2.20.1
>