2016-09-22 15:14 GMT+02:00 Uwe Kleine-König [off-list ref]:

On Mon, Sep 12, 2016 at 11:47:31AM +0200, Richard Genoud wrote:

quoted

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 <redacted>
---
 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.