Re: [PATCH v1] gpio: pca953x: handle short interrupt pulses on PCAL devices
From: Bartosz Golaszewski
Date: Fri Jan 02 2026 - 04:38:11 EST
On Wed, 17 Dec 2025 16:30:25 +0100, Ernest Van Hoecke wrote:
> GPIO drivers with latch input support may miss short pulses on input
> pins even when input latching is enabled. The generic interrupt logic in
> the pca953x driver reports interrupts by comparing the current input
> value against the previously sampled one and only signals an event when
> a level change is observed between two reads.
>
> For short pulses, the first edge is captured when the input register is
> read, but if the signal returns to its previous level before the read,
> the second edge is not observed. As a result, successive pulses can
> produce identical input values at read time and no level change is
> detected, causing interrupts to be missed. Below timing diagram shows
> this situation where the top signal is the input pin level and the
> bottom signal indicates the latched value.
>
> [...]
Applied, thanks!
[1/1] gpio: pca953x: handle short interrupt pulses on PCAL devices
commit: 014a17deb41201449f76df2b20c857a9c3294a7c
Best regards,
--
Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>