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

[Carlo Caione]

On Mon, Jul 6, 2026 at 9:10 PM David Lechner <dlechner at baylibre.com> wrote:
>
> 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.

Yes, but this is a preliminary patch for a much larger effort focused
only on the G700 for now. Since this change essentially disables the
watchdog in U-Boot I prefer to limit it, for now, only to the
platforms where this is actually needed. The same will be done also
for the other platforms in due time.

Cheers,

--
Carlo Caione