[PATCH] configs: mediatek: do not autostart the watchdog on the Genio EVKs

[David Lechner]

On 7/6/26 8:24 AM, Carlo Caione wrote:
> U-Boot autostarts the SoC watchdog (CONFIG_WATCHDOG_AUTOSTART default
> y) and services it from its main loop, but nothing services it after
> ExitBootServices()/bootm: an EFI-booted OS that does not take over the
> watchdog in time is reset mid-boot at a wall-clock-dependent point.
> 
> The MediaTek toprgu can count at most ~16 seconds, once firmware stops
> servicing it at the handoff, the OS has whatever is left of those 16
> seconds.
> 
> On the Genio 700 EVK the generic Ubuntu 26.04 arm64 image is hard-reset
> before its first boot reaches the login prompt: the mtk-wdt driver is
> a module loaded from the rootfs and cannot win that race. Nothing tells
> a generic OS that the watchdog is armed, so the failure is silent and,
> from the user's side, indistinguishable from broken firmware.
> 
> Disable WATCHDOG_AUTOSTART for the Genio EVK boards (mt8365_evk
> directly, mt8188.config for the Genio 510/700).
> 
> Signed-off-by: Carlo Caione <ccaione at baylibre.com>
> ---
>  configs/mt8188.config        | 1 +
>  configs/mt8365_evk_defconfig | 1 +
>  2 files changed, 2 insertions(+)
> 

What about Genio 520/720 (mt8189.config) and Genio 1200 (mt8195.config)?
Seems like the same reasoning would apply to those.

> diff --git a/configs/mt8188.config b/configs/mt8188.config
> index 9dfba6bf99f..26823cf35d2 100644
> --- a/configs/mt8188.config
> +++ b/configs/mt8188.config
> @@ -20,6 +20,7 @@ CONFIG_PINCTRL_MT8188=y
>  CONFIG_BAUDRATE=921600
>  CONFIG_DM_SERIAL=y
>  CONFIG_MTK_SERIAL=y
> +# CONFIG_WATCHDOG_AUTOSTART is not set
>  CONFIG_WDT=y
>  CONFIG_WDT_MTK=y
>  # CONFIG_RANDOM_UUID is not set
> diff --git a/configs/mt8365_evk_defconfig b/configs/mt8365_evk_defconfig
> index 1a385492547..6620f540fd4 100644
> --- a/configs/mt8365_evk_defconfig
> +++ b/configs/mt8365_evk_defconfig
> @@ -29,5 +29,6 @@ CONFIG_DM_REGULATOR_MT6357=y
>  CONFIG_BAUDRATE=921600
>  CONFIG_DM_SERIAL=y
>  CONFIG_MTK_SERIAL=y
> +# CONFIG_WATCHDOG_AUTOSTART is not set
>  CONFIG_WDT=y
>  CONFIG_WDT_MTK=y