When CONFIG_SERIAL_FSL_LINFLEXUART=y and CONFIG_PRINTK is not set, one compilation error is found as below: drivers/tty/serial/fsl_linflexuart.c: In function linflex_earlycon_putchar: drivers/tty/serial/fsl_linflexuart.c:608:31: error: CONFIG_LOG_BUF_SHIFT undeclared (first use in this function); did you mean CONFIG_ISA_BUS_API? if (earlycon_buf.len >= 1 << CONFIG_LOG_BUF_SHIFT) ^~~~~~~~~~~~~~~~~~~~ CONFIG_ISA_BUS_API This because CONFIG_LOG_BUF_SHIFT is depended on CONFIG_PRINTK, fix this by adding dependence for CONFIG_SERIAL_FSL_LINFLEXUART. Fixes: b953815b819b ("tty: serial: Add linflexuart driver for S32V234") Signed-off-by: Mao Wenan <maowenan@xxxxxxxxxx> --- drivers/tty/serial/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index d9caf3242b25..4789b5d62f63 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1392,6 +1392,7 @@ config SERIAL_FSL_LPUART_CONSOLE config SERIAL_FSL_LINFLEXUART tristate "Freescale linflexuart serial port support" + depends on PRINTK select SERIAL_CORE help Support for the on-chip linflexuart on some Freescale SOCs. -- 2.20.1