Re: [PATCH v7 08/15] gpiolib: regmap: add write_data_after_dir quirk

[Andy Shevchenko]

On Tue, Sep 15, 2026 at 07:15:38PM +0800, Long Zhao via B4 Relay wrote:

> Some controllers ignore data-register writes while a line is still an
> input. Optionally write the output value again after switching the
> direction, matching the existing PL061 behaviour.

...

> -	gpio_regmap_set(chip, offset, value);
> +	ret = gpio_regmap_set(chip, offset, value);
> +	if (ret)
> +		return ret;

I think that this might lead to regressions when the end driver just leaves
the output in the previous state in case of errors. In any case, even if this
is a correct update, it needs to be done separately with the justification
that shows that all current users won't have regressions or the regression is
actually a fix of the behaviour.

> +	ret = gpio_regmap_set_direction(chip, offset, true);
> +	if (ret)
> +		return ret;
>  
> -	return gpio_regmap_set_direction(chip, offset, true);
> +	/*
> +	 * gpio value is set again, because pl061 doesn't allow to set value of
> +	 * a gpio pin before configuring it in OUT mode.
> +	 */
> +	if (gpio->write_data_after_dir)
> +		return gpio_regmap_set(chip, offset, value);

Taking the above into account I'm not sure if we want the inconsistency with
the above. Perhaps also ignore the returned value for now?

> +	return 0;

-- 
With Best Regards,
Andy Shevchenko