8250_mid uses rational_best_approximation() function, so the driver needs to select CONFIG_RATIONAL option. This fixes build error when CONFIG_RATIONAL is not enabled: drivers/built-in.o: In function `mid8250_set_termios': 8250_mid.c:(.text+0x10169a): undefined reference to `rational_best_approximation' Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> --- drivers/tty/serial/8250/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig index e6f5e12..6412f14 100644 --- a/drivers/tty/serial/8250/Kconfig +++ b/drivers/tty/serial/8250/Kconfig @@ -373,6 +373,7 @@ config SERIAL_8250_MID depends on SERIAL_8250 && PCI select HSU_DMA if SERIAL_8250_DMA select HSU_DMA_PCI if X86_INTEL_MID + select RATIONAL help Selecting this option will enable handling of the extra features present on the UART found on Intel Medfield SOC and various other -- 2.6.2 -- 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