serial: bfin_uart: Don't switch baud rate untill the transfer buffer is empty.
set_termios may be invoked before the former data transfer is completed.
Block until the tranfer is done.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/bfin_uart.c b/drivers/tty/serial/bfin_uart.c
index 18cf45a..e6a008f 100644
--- a/drivers/tty/serial/bfin_uart.c
+++ b/drivers/tty/serial/bfin_uart.c
@@ -799,6 +799,7 @@
unsigned long flags;
unsigned int baud, quot;
unsigned int ier, lcr = 0;
+ unsigned long timeout;
switch (termios->c_cflag & CSIZE) {
case CS8:
@@ -868,6 +869,14 @@
UART_SET_ANOMALY_THRESHOLD(uart, USEC_PER_SEC / baud * 15);
+ /* Wait till the transfer buffer is empty */
+ timeout = jiffies + msecs_to_jiffies(10);
+ while (UART_GET_GCTL(uart) & UCEN && !(UART_GET_LSR(uart) & TEMT))
+ if (time_after(jiffies, timeout)) {
+ dev_warn(port->dev, "timeout waiting for TX buffer empty\n");
+ break;
+ }
+
/* Disable UART */
ier = UART_GET_IER(uart);
UART_PUT_GCTL(uart, UART_GET_GCTL(uart) & ~UCEN);