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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 <ssreedharan@mvista.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sudhir Sreedharan 2014-10-17 18:09:18 +05:30 committed by Greg Kroah-Hartman
parent 513e438581
commit edf4edacb3
1 changed files with 5 additions and 2 deletions
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7
drivers/tty/serial/8250/8250_core.c
View File

@ -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: