On Mon, Jun 03, 2019 at 10:33:32AM +0200, Stefan Roese wrote: > From: Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx> > > This patch permits the usage for GPIOs to control > the CTS/RTS/DTR/DSR/DCD/RI signals. > + if (up->gpios) { > + mctrl_gpio_set(up->gpios, mctrl_gpio); > + } ... > + if (up->gpios) { > + mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio); > + } ... > + gpios = mctrl_gpio_init(&uart->port, 0); > + if (IS_ERR(gpios)) { > + if (PTR_ERR(gpios) != -ENOSYS) > + return PTR_ERR(gpios); > + } ... > + if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(up->gpios, > + UART_GPIO_RTS))) { > + } ... > - if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) { > + if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW > + && IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(up->gpios, > + UART_GPIO_RTS))) { > } ... > + if (up->gpios) > + mctrl_gpio_disable_ms(up->gpios); ... > + if (up->gpios) > + mctrl_gpio_enable_ms(up->gpios); ... > + if (up->gpios) > + return mctrl_gpio_get(up->gpios, &ret); Can we rather make this mimic the gpiod_get_optional() API? So, if we get an error, it's an error, otherwise with NULL pointer the operations goes to be no-op. [IS_ERR_OR_NULL() -> IS_ERR(), if (up->gpios) -> /dev/null, etc] -- With Best Regards, Andy Shevchenko