Re: [PATCHv2 1/3] serial: mctrl_gpio: implement mctrl_gpio_use_rtscts

From: Richard Genoud
Date: Mon Sep 26 2016 - 07:57:49 EST


2016-09-22 15:14 GMT+02:00 Uwe Kleine-KÃnig <u.kleine-koenig@xxxxxxxxxxxxxx>:
> On Mon, Sep 12, 2016 at 11:47:31AM +0200, Richard Genoud wrote:
>> This function returns true if CTS and RTS are used as GPIOs.
>> Some drivers (like atmel_serial) needs to know if the flow control is
>> handled by the controller or by GPIOs.
>>
>> Signed-off-by: Richard Genoud <richard.genoud@xxxxxxxxx>
>> ---
>> drivers/tty/serial/serial_mctrl_gpio.c | 8 ++++++++
>> drivers/tty/serial/serial_mctrl_gpio.h | 10 ++++++++++
>> 2 files changed, 18 insertions(+)
>>
>> diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c
>> index d2da6aa7f27d..93bed8c99796 100644
>> --- a/drivers/tty/serial/serial_mctrl_gpio.c
>> +++ b/drivers/tty/serial/serial_mctrl_gpio.c
>> @@ -17,6 +17,7 @@
>> #include <linux/err.h>
>> #include <linux/device.h>
>> #include <linux/irq.h>
>> +#include <linux/err.h>
>> #include <linux/gpio/consumer.h>
>> #include <linux/termios.h>
>> #include <linux/serial_core.h>
>> @@ -72,6 +73,13 @@ struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
>> }
>> EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod);
>>
>> +bool mctrl_gpio_use_rtscts(struct mctrl_gpios *gpios)
>> +{
>> + return !IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) &&
>> + !IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_RTS));
>
> mctrl_gpio_to_gpiod cannot return an error pointer. So this is
> (surprise!) a wrong usage of IS_ERR_OR_NULL.

I see, your commit 1d267ea6539f266352f ("serial: mctrl-gpio: simplify
init routine") removed the need of IS_ERR_OR_NULL().
I'll change that.

Thanks !

Richard.