The Mediatek 8250 driver has a 'bool' Kconfig symbol, but that breaks when SERIAL_8250 is a loadable module: drivers/tty/built-in.o: In function `mtk8250_set_termios': :(.text+0x1bee8): undefined reference to `serial8250_do_set_termios' :(.text+0x1bf10): undefined reference to `uart_get_baud_rate' :(.text+0x1c09c): undefined reference to `uart_get_divisor' drivers/tty/built-in.o: In function `mtk8250_do_pm': :(.text+0x1c0d0): undefined reference to `serial8250_do_pm' drivers/tty/built-in.o: In function `mtk8250_probe': :(.text+0x1c2e4): undefined reference to `serial8250_register_8250_port' serial/8250/8250_mtk.c:287:242: error: data definition has no type or storage class [-Werror] serial/8250/8250_mtk.c:287:122: error: 'mtk8250_platform_driver_init' defined but not used [-Werror=unused-function] This changes the symbol to a 'tristate', so the dependency on SERIAL_8250 also works when that is set to 'm'. To actually build the driver, we also need to include <linux/module.h>. Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- drivers/tty/serial/8250/8250_mtk.c | 3 ++- drivers/tty/serial/8250/Kconfig | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c index 6ecc6e3e82dc..55be90c1d85e 100644 --- a/drivers/tty/serial/8250/8250_mtk.c +++ b/drivers/tty/serial/8250/8250_mtk.c @@ -19,6 +19,7 @@ #include <linux/module.h> #include <linux/of_irq.h> #include <linux/of_platform.h> +#include <linux/module.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/serial_8250.h> @@ -303,7 +304,7 @@ static struct platform_driver mtk8250_platform_driver = { }; module_platform_driver(mtk8250_platform_driver); -#ifdef CONFIG_SERIAL_8250_CONSOLE +#if defined(CONFIG_SERIAL_8250_CONSOLE) && !defined(MODULE) static int __init early_mtk8250_setup(struct earlycon_device *device, const char *options) { diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig index 67ad6b0d595b..6ae0fae4f796 100644 --- a/drivers/tty/serial/8250/Kconfig +++ b/drivers/tty/serial/8250/Kconfig @@ -370,7 +370,7 @@ config SERIAL_8250_LPC18XX serial port, say Y to this option. If unsure, say Y. config SERIAL_8250_MT6577 - bool "Mediatek serial port support" + tristate "Mediatek serial port support" depends on SERIAL_8250 && ARCH_MEDIATEK help If you have a Mediatek based board and want to use the -- 2.7.0 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html