[PATCH 3/9] tty: xuartps: Always enable transmitter in start_tx

Soren Brinkmann soren.brinkmann at xilinx.com
Tue Nov 3 16:20:44 PST 2015


start_tx must start transmitting characters. Regardless of the state of
the circular buffer, always enable the transmitter hardware.

Signed-off-by: Soren Brinkmann <soren.brinkmann at xilinx.com>
---
 drivers/tty/serial/xilinx_uartps.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index dc1987f3dc0a..5edd1efca015 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -512,9 +512,6 @@ static void cdns_uart_start_tx(struct uart_port *port)
 {
 	unsigned int status, numbytes = port->fifosize;
 
-	if (uart_circ_empty(&port->state->xmit) || uart_tx_stopped(port))
-		return;
-
 	/*
 	 * Set the TX enable bit and clear the TX disable bit to enable the
 	 * transmitter.
@@ -524,6 +521,9 @@ static void cdns_uart_start_tx(struct uart_port *port)
 	status |= CDNS_UART_CR_TX_EN;
 	writel(status, port->membase + CDNS_UART_CR_OFFSET);
 
+	if (uart_circ_empty(&port->state->xmit) || uart_tx_stopped(port))
+		return;
+
 	while (numbytes-- && ((readl(port->membase + CDNS_UART_SR_OFFSET) &
 				CDNS_UART_SR_TXFULL)) != CDNS_UART_SR_TXFULL) {
 		/* Break if no more data available in the UART buffer */
-- 
2.6.2.3.ga463a5b




More information about the linux-arm-kernel mailing list