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authorGeert Uytterhoeven2015-11-18 16:20:44 +0100
committerGeert Uytterhoeven2015-12-17 11:18:21 +0100
commita67969b5fd366d488ffa1defd5256e8c3a87434d (patch)
tree95bb666b37a6ec72618b4c35cd177c0aa99398bd /drivers/tty
parentbdcb3826976e60204cce52470c01bb9541e547b3 (diff)
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 <geert+renesas@glider.be> Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/sh-sci.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 05ac15336e4f..136ad2f63341 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);