Re: [PATCH v2] watchdog: mediatek: acknowledge pretimeout interrupt

[Guenter Roeck]

On 8/27/26 19:08, Tzung-Bi Shih wrote:
> On Thu, Aug 27, 2026 at 06:54:03AM -0700, Guenter Roeck wrote:
> > On Thu, Aug 27, 2026 at 05:26:12PM +0800, Wanming Gao wrote:
> > > The MediaTek watchdog pretimeout interrupt is level-triggered and does
> > > not have a separate acknowledge register. The interrupt is cleared by
> > > changing WDT_MODE_IRQ_LEVEL_EN and then restoring it to its original
> > > state. Without this transition, the interrupt may remain asserted and
> > > cause an interrupt storm.
> > >
> > > After changing WDT_MODE_IRQ_LEVEL_EN, wait 70 us before restoring it.
> > > This is longer than two 32 kHz watchdog clock cycles, allowing the
> > > level change to propagate across the clock domain.
> > >
> > > WDT_MODE is also updated by the watchdog start, stop, and pretimeout
> > > operations. Protect its read-modify-write sequences and the complete
> > > IRQ acknowledge sequence with the watchdog spinlock so that concurrent
> > > updates cannot overwrite the temporary IRQ level state.
> > >
> > > Signed-off-by: Wanming Gao <wanming.gao@xxxxxxxxxxxx>
> >
> > Applied.
>
> Might be a bit late, but tested on a MT8196 board:
> Tested-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>
> Reviewed-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>

Never too late, really, unless I already sent a pull request.
Also, I have not pushed anything out, waiting for v7.3-rc1.

Thanks,
Guenter