Re: [PATCH] pinctrl-mcp23s08: Reset all pins to input at probe

[Linus Walleij]

On Fri, Mar 14, 2025 at 4:18 PM Mike Looijmans <mike.looijmans@xxxxxxxx> wrote:


> At startup, the driver just assumes that all registers have their
> default values. But after a soft reset, the chip will just be in the
> state it was, and some pins may have been configured as outputs. Any
> modification of the output register will cause these pins to be driven
> low, which leads to unexpected/unwanted effects. To prevent this from
> happening, set the chip's IO configuration register to a known safe
> mode (all inputs) before toggling any other bits.
>
> Signed-off-by: Mike Looijmans <mike.looijmans@xxxxxxxx>

Patch tentatively applied for v6.16.

CC to some mcp23s08 users so they can check it out.

Yours,
Linus Walleij