From edf4edacb331caf326a2e0f15d81c549bd9bede7 Mon Sep 17 00:00:00 2001 From: Sudhir Sreedharan Date: Fri, 17 Oct 2014 18:09:18 +0530 Subject: [PATCH] tty: serial: 8250_core: restore the LCR register in set_sleep In ST16650V2 based serial uarts, while initalizing the PM state, LCR registers are being initialized to 0 in serial8250_set_sleep(). If console port is already initialized and being used, this will throws garbage in the console. Signed-off-by: Sudhir Sreedharan Reviewed-by: Peter Hurley Tested-by: Kevin Hilman Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_core.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index ca5cfdc1459a..b17048756941 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -595,6 +595,7 @@ static void serial8250_rpm_put_tx(struct uart_8250_port *p) */ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) { + unsigned char lcr = 0, efr = 0; /* * Exar UARTs have a SLEEP register that enables or disables * each UART to enter sleep mode separately. On the XR17V35x the @@ -611,6 +612,8 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) if (p->capabilities & UART_CAP_SLEEP) { if (p->capabilities & UART_CAP_EFR) { + lcr = serial_in(p, UART_LCR); + efr = serial_in(p, UART_EFR); serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(p, UART_EFR, UART_EFR_ECB); serial_out(p, UART_LCR, 0); @@ -618,8 +621,8 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) serial_out(p, UART_IER, sleep ? UART_IERX_SLEEP : 0); if (p->capabilities & UART_CAP_EFR) { serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B); - serial_out(p, UART_EFR, 0); - serial_out(p, UART_LCR, 0); + serial_out(p, UART_EFR, efr); + serial_out(p, UART_LCR, lcr); } } out: -- 2.20.1