Merge tag 'v4.9.144' into 4.9-2.3.x-imx

This is the 4.9.144 stable release

1 files changed, 13 insertions, 6 deletions

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 793395451982..ea6b62cece88 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -661,7 +661,7 @@ static void sc16is7xx_handle_tx(struct uart_port *port)
 		uart_write_wakeup(port);
 }
 
-static void sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
+static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
 {
 	struct uart_port *port = &s->p[portno].port;
 
@@ -670,7 +670,7 @@ static void sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
 
 		iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
 		if (iir & SC16IS7XX_IIR_NO_INT_BIT)
-			break;
+			return false;
 
 		iir &= SC16IS7XX_IIR_ID_MASK;
 
@@ -692,16 +692,23 @@ static void sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
 					    port->line, iir);
 			break;
 		}
-	} while (1);
+	} while (0);
+	return true;
 }
 
 static void sc16is7xx_ist(struct kthread_work *ws)
 {
 	struct sc16is7xx_port *s = to_sc16is7xx_port(ws, irq_work);
-	int i;
 
-	for (i = 0; i < s->devtype->nr_uart; ++i)
-		sc16is7xx_port_irq(s, i);
+	while (1) {
+		bool keep_polling = false;
+		int i;
+
+		for (i = 0; i < s->devtype->nr_uart; ++i)
+			keep_polling |= sc16is7xx_port_irq(s, i);
+		if (!keep_polling)
+			break;
+	}
 }
 
 static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)