[PATCH 7/7] serial: uartps: Prevent writes when the controller is disabled

[Shubhrajyoti Datta]

Prevent writing to the fifo if the controller is disabled.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
---
 drivers/tty/serial/xilinx_uartps.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 81ba69c57716..f629c4ca940f 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -1150,6 +1150,13 @@ static struct uart_driver cdns_uart_uart_driver;
  */
 static void cdns_uart_console_putchar(struct uart_port *port, unsigned char ch)
 {
+	unsigned int ctrl_reg;
+
+	ctrl_reg = readl(port->membase + CDNS_UART_CR);
+	while (ctrl_reg & CDNS_UART_CR_TX_DIS) {
+		ctrl_reg = readl(port->membase + CDNS_UART_CR);
+		cpu_relax();
+	}
 	while (readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)
 		cpu_relax();
 	writel(ch, port->membase + CDNS_UART_FIFO);
-- 
2.25.1