From: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
In case the cable is not connected then the target gets into
an infinite wait for tx empty.
Add a timeout to the tx empty wait.
Reported-by: Jean-Francois Dagenais <jeff.dagenais@xxxxxxxxx>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
---
v3:
update the print to dev_err
drivers/tty/serial/xilinx_uartps.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 8850790..d872b25 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -26,12 +26,14 @@
#include <linux/of.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
+#include <linux/iopoll.h>
#define CDNS_UART_TTY_NAME "ttyPS"
#define CDNS_UART_NAME "xuartps"
#define CDNS_UART_MAJOR 0 /* use dynamic node allocation */
#define CDNS_UART_FIFO_SIZE 64 /* FIFO size */
#define CDNS_UART_REGISTER_SPACE 0x1000
+#define TX_TIMEOUT 500000
/* Rx Trigger level */
static int rx_trigger_level = 56;
@@ -688,14 +690,18 @@ static void cdns_uart_set_termios(struct uart_port *port,
unsigned int cval = 0;
unsigned int baud, minbaud, maxbaud;
unsigned long flags;
- unsigned int ctrl_reg, mode_reg;
+ unsigned int ctrl_reg, mode_reg, val;
+ int err;
/* Wait for the transmit FIFO to empty before making changes */
if (!(readl(port->membase + CDNS_UART_CR) &
CDNS_UART_CR_TX_DIS)) {
- while (!(readl(port->membase + CDNS_UART_SR) &
- CDNS_UART_SR_TXEMPTY)) {
- cpu_relax();
+ err = readl_poll_timeout(port->membase + CDNS_UART_SR,
+ val, (val & CDNS_UART_SR_TXEMPTY),
+ 1000, TX_TIMEOUT);
+ if (err) {
+ dev_err(port->dev, "timed out waiting for tx empty");
+ return;
}
}
spin_lock_irqsave(&port->lock, flags);
--
2.1.1
