Re: [PATCH v5 2/3] tty/serial: at91: use mctrl_gpio helpers

[Alexander Shiyan]

Hello.

Понедельник,  3 марта 2014, 12:11 +01:00 от Richard Genoud <noreply.rgenoud at gmail.com>:
> On sam9x5, dedicated CTS (and RTS) pins are unusable together with the
> LCDC, the EMAC, or the MMC because they share the same line.
> 
> Moreover, the USART controller doesn't handle DTR/DSR/DCD/RI signals,
> so we have to control them via GPIO.
> 
> This patch permits to use GPIOs to control the CTS/RTS/DTR/DSR/DCD/RI
> signals.
> 
> Signed-off-by: Richard Genoud <richard.genoud at gmail.com>

...
> +static int atmel_init_gpios(struct atmel_uart_port *p, struct device *dev)
> +{
> +	int err = 0;
> +
> +	p->gpios = mctrl_gpio_init(dev, 0);
> +	if (IS_ERR_OR_NULL(p->gpios))
> +		err = PTR_ERR(p->gpios);
> +
> +	return err;
> +}

So what happen if mctrl_gpio_init() returns NULL?
Your function return 0, ie not an error.
Just use IS_ERR() macro here.

Thanks.
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