From a67969b5fd366d488ffa1defd5256e8c3a87434d Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Wed, 18 Nov 2015 16:20:44 +0100 Subject: [PATCH] serial: sh-sci: Don't overwrite clock selection in serial_console_write() Blindly writing the default configuration value into the SCSCR register may change the clock selection bits, breaking the serial console if the current driver settings differ from the default settings. Keep the current clock selection bits to prevent this from happening on e.g. r8a7791/koelsch when support for the BRG will be added. Signed-off-by: Geert Uytterhoeven Reviewed-by: Laurent Pinchart Acked-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 05ac15336e4f9..136ad2f633413 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -2420,7 +2420,7 @@ static void serial_console_write(struct console *co, const char *s, { struct sci_port *sci_port = &sci_ports[co->index]; struct uart_port *port = &sci_port->port; - unsigned short bits, ctrl; + unsigned short bits, ctrl, ctrl_temp; unsigned long flags; int locked = 1; @@ -2432,9 +2432,11 @@ static void serial_console_write(struct console *co, const char *s, else spin_lock(&port->lock); - /* first save the SCSCR then disable the interrupts */ + /* first save SCSCR then disable interrupts, keep clock source */ ctrl = serial_port_in(port, SCSCR); - serial_port_out(port, SCSCR, sci_port->cfg->scscr); + ctrl_temp = (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) | + (ctrl & (SCSCR_CKE1 | SCSCR_CKE0)); + serial_port_out(port, SCSCR, ctrl_temp); uart_console_write(port, s, count, serial_console_putchar); -- 2.30.2