Re: [PATCH] watchdog: mediatek: Apply the driver's mode to a watchdog left running

[Guenter Roeck]

On Wed, Sep 23, 2026 at 10:10:41PM -0500, Ryan Brue wrote:
> When the bootloader leaves the watchdog enabled, probe only marks it
> running and sets the timeout, so WDT_MODE keeps whatever the bootloader
> wrote. The Amazon Fire HD 10 (2017) bootloader leaves dual mode with the
> bark IRQ enabled, and no pretimeout is configured, so each timeout only
> raises the IRQ and restarts the count: with the 20 s timeout systemd
> sets, a hung system was reset after 37.95-39.76 s, and after 18.25-20.92 s
> once IRQ_EN was cleared by hand.
> 
> Program the mode as mtk_wdt_start() does, which also applies
> mediatek,disable-extrst and mediatek,reset-by-toprgu to a running
> watchdog; read those two properties first.
> 
> Fixes: bbece05c0d3a ("watchdog: mtk_wdt: Remove mtk_wdt_stop() in probe() to prevent the system freeze and it doesn't reboot by watchdog problem")
> Assisted-by: LLM
> Signed-off-by: Ryan Brue <ryanbrue.dev@xxxxxxxxx>
> ---

Applied.

Thanks,
Guenter