Runtime tested on Mikrotik RB532 board. Thanks goes to Geert Uytterhoeven for the explanation of the problem. "I'm afraid this is not gonna help. When the port is unregistered, its type will be reset to PORT_UNKNOWN. So before registering it again, its type must be set again the actual serial driver, cfr. the change to of_serial.c." Signed-off-by: Waldemar Brodkorb <wbx@xxxxxxxxxxx> --- arch/mips/rb532/devices.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/mips/rb532/devices.c b/arch/mips/rb532/devices.c index 3af00b2..ba61268 100644 --- a/arch/mips/rb532/devices.c +++ b/arch/mips/rb532/devices.c @@ -223,6 +223,7 @@ static struct platform_device rb532_wdt = { static struct plat_serial8250_port rb532_uart_res[] = { { + .type = PORT_16550A, .membase = (char *)KSEG1ADDR(REGBASE + UART0BASE), .irq = UART0_IRQ, .regshift = 2, -- 1.7.10.4