Re: [PATCH 1/2] gpio: rdc321x: Fix off-by-one for ngpio setting

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Fri, Apr 11, 2014 at 8:14 AM, Axel Lin <axel.lin@xxxxxxxxxx> wrote:

> The valid gpio is GPIO0 ~ GPIO58, so ngpio should be RDC321X_MAX_GPIO + 1.
>
> Signed-off-by: Axel Lin <axel.lin@xxxxxxxxxx>
(...)
> -       rdc321x_gpio_dev->chip.ngpio = pdata->max_gpios;
> +       rdc321x_gpio_dev->chip.ngpio = pdata->max_gpios + 1;

This is counter-intuitive. "max_gpios" should be a name for the
maximum number of gpios right? Not the maximum number of
GPIOs minus one!

It is better to patch include/linux/mfd/rdc321x.h:

-#define RDC321X_MAX_GPIO    58
+#define RDC321X_MAX_GPIO    59

Which establishes the true character of this device.

Yours,
Linus Walleij
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