Re: [PATCH v2] gpiolib-acpi: Preserve non direction flags when updating gpiod_flags

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

On Mon, Dec 31, 2018 at 09:55:21PM +0100, Hans de Goede wrote:
> __acpi_gpio_update_gpiod_flags purpose is to make the gpiod_flags used
> when requesting a GPIO match the restrictions from the ACPI resource,
> as stored in acpi_gpio_info.flags.
> 
> But acpi_gpio_info.flags only contains direction info, and the
> requester may have passed in special non-direction flags like
> GPIOD_FLAGS_BIT_NONEXCLUSIVE, which we currently clobber.
> 
> This commit modifies __acpi_gpio_update_gpiod_flags to preserve these
> special flags, so that a requested of an ACPI GPIO can e.g. pass
> GPIOD_FLAGS_BIT_NONEXCLUSIV and have it work as intended.
> 
> Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> Changes in v2:
> -Fold 2 statements into 1 as suggested by Andy
> ---
>  drivers/gpio/gpiolib-acpi.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
> index 091a3784720d..800fb0901283 100644
> --- a/drivers/gpio/gpiolib-acpi.c
> +++ b/drivers/gpio/gpiolib-acpi.c
> @@ -469,6 +469,9 @@ acpi_gpio_to_gpiod_flags(const struct acpi_resource_gpio *agpio)
>  static int
>  __acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, enum gpiod_flags update)
>  {
> +	const enum gpiod_flags mask =
> +		GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT |
> +		GPIOD_FLAGS_BIT_DIR_VAL;

I'm just wondering if we can introduce in consumer.h something like

#define GPIOD_FLAGS_BIT_DIR_MASK	GENMASK(2, 0)

and use it here.

>  	int ret = 0;
>  
>  	/*
> @@ -489,7 +492,7 @@ __acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, enum gpiod_flags update)
>  		if (((*flags & GPIOD_FLAGS_BIT_DIR_SET) && (diff & GPIOD_FLAGS_BIT_DIR_OUT)) ||
>  		    ((*flags & GPIOD_FLAGS_BIT_DIR_OUT) && (diff & GPIOD_FLAGS_BIT_DIR_VAL)))
>  			ret = -EINVAL;
> -		*flags = update;
> +		*flags = (*flags & ~mask) | (update & mask);
>  	}
>  	return ret;
>  }
> -- 
> 2.19.1
> 

-- 
With Best Regards,
Andy Shevchenko