Restarting the transmitter even if the circ buffer is empty may be
necessary to push out remaining data when the port is restarted after
being stopped.
Cc: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xxxxxxxxxx>
Reviewed-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
---
v3:
- changed this patch to not always enable the transmitter, but keep the
check for uart_tx_stopped() in place, as suggested by Peter, whose
explanation I also stole for the new commit message (thx)
---
drivers/tty/serial/xilinx_uartps.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 2c98c357d9a0..6a7cd4e057ae 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -512,7 +512,7 @@ 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))
+ if (uart_tx_stopped(port))
return;
/*
@@ -524,6 +524,9 @@ 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))
+ 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 */
--
2.6.3.3.g9bb996a
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