From 0e3e143e5d1e7be65331cdf6d100b08bc6c15b72 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Mon, 9 Mar 2015 16:27:16 -0400 Subject: [PATCH] serial: 8250_early: Assume uart already initialized if no baud option The option string is not supplied if the earlycon is started via devicetree and OF_EARLYCON_DECLARE(). The option string is also not required if started via kernel command line parameters of the form: earlycon=uart,mmio, console=uart,mmio, If earlycon_device->baud is 0, then an option string was not supplied. In this case, assume the uart has already been initialized by the bootloader or firmware. Acked-by: Rob Herring Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_early.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c index d7b831bcf367..1701d00fd9f6 100644 --- a/drivers/tty/serial/8250/8250_early.c +++ b/drivers/tty/serial/8250/8250_early.c @@ -149,12 +149,18 @@ static int __init early_serial8250_setup(struct earlycon_device *device, return 0; if (!device->baud) { + struct uart_port *port = &device->port; + unsigned int ier; + device->baud = probe_baud(&device->port); snprintf(device->options, sizeof(device->options), "%u", device->baud); - } - init_port(device); + /* assume the device was initialized, only mask interrupts */ + ier = serial8250_early_in(port, UART_IER); + serial8250_early_out(port, UART_IER, ier & UART_IER_UUE); + } else + init_port(device); device->con->write = early_serial8250_write; return 0; -- 2.39.2