1 files changed, 22 insertions, 16 deletions

diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index 4f5f161896a1..f85b8e6d0346 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -678,11 +678,18 @@ static void mxs_auart_settermios(struct uart_port *u,
 
 static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
 {
-	u32 istatus, istat;
+	u32 istat;
 	struct mxs_auart_port *s = context;
 	u32 stat = readl(s->port.membase + AUART_STAT);
 
-	istatus = istat = readl(s->port.membase + AUART_INTR);
+	istat = readl(s->port.membase + AUART_INTR);
+
+	/* ack irq */
+	writel(istat & (AUART_INTR_RTIS
+		| AUART_INTR_TXIS
+		| AUART_INTR_RXIS
+		| AUART_INTR_CTSMIS),
+			s->port.membase + AUART_INTR_CLR);
 
 	if (istat & AUART_INTR_CTSMIS) {
 		uart_handle_cts_change(&s->port, stat & AUART_STAT_CTS);
@@ -702,12 +709,6 @@ static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
 		istat &= ~AUART_INTR_TXIS;
 	}
 
-	writel(istatus & (AUART_INTR_RTIS
-		| AUART_INTR_TXIS
-		| AUART_INTR_RXIS
-		| AUART_INTR_CTSMIS),
-			s->port.membase + AUART_INTR_CLR);
-
 	return IRQ_HANDLED;
 }
 
@@ -850,7 +851,7 @@ auart_console_write(struct console *co, const char *str, unsigned int count)
 	struct mxs_auart_port *s;
 	struct uart_port *port;
 	unsigned int old_ctrl0, old_ctrl2;
-	unsigned int to = 1000;
+	unsigned int to = 20000;
 
 	if (co->index >= MXS_AUART_PORTS || co->index < 0)
 		return;
@@ -871,18 +872,23 @@ auart_console_write(struct console *co, const char *str, unsigned int count)
 
 	uart_console_write(port, str, count, mxs_auart_console_putchar);
 
-	/*
-	 * Finally, wait for transmitter to become empty
-	 * and restore the TCR
-	 */
+	/* Finally, wait for transmitter to become empty ... */
 	while (readl(port->membase + AUART_STAT) & AUART_STAT_BUSY) {
+		udelay(1);
 		if (!to--)
 			break;
-		udelay(1);
 	}
 
-	writel(old_ctrl0, port->membase + AUART_CTRL0);
-	writel(old_ctrl2, port->membase + AUART_CTRL2);
+	/*
+	 * ... and restore the TCR if we waited long enough for the transmitter
+	 * to be idle. This might keep the transmitter enabled although it is
+	 * unused, but that is better than to disable it while it is still
+	 * transmitting.
+	 */
+	if (!(readl(port->membase + AUART_STAT) & AUART_STAT_BUSY)) {
+		writel(old_ctrl0, port->membase + AUART_CTRL0);
+		writel(old_ctrl2, port->membase + AUART_CTRL2);
+	}
 
 	clk_disable(s->clk);
 }