Re: [PATCH] gpio: revert get() to non-errorprogating behaviour

[Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>]

On Thu 17 Dec 01:21 PST 2015, Linus Walleij wrote:

> commit e20538b82f1ffcc06e68feb117f24f211cff7a4d
> "gpio: Propagate errors from chip->get()"
> started to propagate errors from the .get() functions since
> we can get errors from the infrastructure of e.g. slowbus
> GPIO expanders.
> 
> However it turns out a bunch of drivers relied on the core
> to clamp the value, so we need to revert to the old behaviour
> and go over all drivers and fix them to conform to the
> expectations of the core before we go back to propagating
> the error code.
> 

Okay, lets fix the drivers and then revert this revert.

> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>

Acked-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>

> Cc: Vladimir Zapolskiy <vladimir_zapolskiy@xxxxxxxxxx>
> Reported-by: Michael Trimarchi <michael@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
>  drivers/gpio/gpiolib.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 2a91f3287e3b..4e4c3083ae56 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -1279,7 +1279,13 @@ static int _gpiod_get_raw_value(const struct gpio_desc *desc)
>  	chip = desc->chip;
>  	offset = gpio_chip_hwgpio(desc);
>  	value = chip->get ? chip->get(chip, offset) : -EIO;
> -	value = value < 0 ? value : !!value;
> +	/*
> +	 * FIXME: fix all drivers to clamp to [0,1] or return negative,
> +	 * then change this to:
> +	 * value = value < 0 ? value : !!value;
> +	 * so we can properly propagate error codes.
> +	 */
> +	value = !!value;
>  	trace_gpio_value(desc_to_gpio(desc), 1, value);
>  	return value;
>  }

Regards,
Bjorn
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