Re: [PATCH] watchdog: bd96801_wdt: Fix timeout for enabled WDG

[Guenter Roeck <linux@roeck-us.net>]

On Fri, Jul 31, 2026 at 12:36:28PM +0300, Matti Vaittinen wrote:
> From: Matti Vaittinen <mazziesaccount@gmail.com>
> 
> When watchdog is enabled at the probe time, the bd96801 driver retrieves
> the timeout configuration from the registers to set-up the heart-beat
> values.
> 
> As Sashiko pointed out at
> https://lore.kernel.org/all/20260722085819.495211F000E9@smtp.kernel.org/
> the timeout values are incorrectly computed in driver, resulting wrong
> heartbeat. This leads to devere problems if watchdog was enabled at probe
> time.
> 
> According to the data-sheet, the "too fast" ping limit is configured as
> multiple of FASTNG_MIN. Furthermore, the "too slow" ping limit is
> configured as multiples of "too fast" timeout. The FASTNG_MIN is set to
> 11, meaning 1.1 mS and "too fast" and "too slow" limits are computed from
> this. Hence, converting the limits to mS should be done by dividing by 10,
> not by dividing by USEC_PER_MSEC.
> 
> Fix this by dividing the timeout values with correct scaling factor.
> 
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> Fixes: 09dad69757b6 ("watchdog: ROHM BD96801 PMIC WDG driver")
> ---
> 
> Also, drop an extra whitespace while editing the file - feeling like
> that single whitespace fix doesn't warrant own patch. Just let me know if
> I feel wrong ;)

No problem (since you let me know and didn't do it silently).

Applied.

Thanks,
Guenter