---

yaml
---
r: 287056
b: refs/heads/master
c: d8d8ffa
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 43cf7c0bebf50d0b68aa42ae6d24cf08e3f24823
+refs/heads/master: d8d8ffa477831b713ddfa2ad4d0ca545f3b567e5

trunk/drivers/tty/serial/amba-pl011.c

@@ -159,6 +159,7 @@ struct uart_amba_port {
 	unsigned int		fifosize;	/* vendor-specific */
 	unsigned int		lcrh_tx;	/* vendor-specific */
 	unsigned int		lcrh_rx;	/* vendor-specific */
+	unsigned int		old_cr;		/* state during shutdown */
 	bool			autorts;
 	char			type[12];
 	bool			interrupt_may_hang; /* vendor-specific */
@@ -1411,7 +1412,9 @@ static int pl011_startup(struct uart_port *port)
 	while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_BUSY)
 		barrier();
 
-	cr = UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE;
+	/* restore RTS and DTR */
+	cr = uap->old_cr & (UART011_CR_RTS | UART011_CR_DTR);
+	cr |= UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE;
 	writew(cr, uap->port.membase + UART011_CR);
 
 	/* Clear pending error interrupts */
@@ -1469,6 +1472,7 @@ static void pl011_shutdown_channel(struct uart_amba_port *uap,
 static void pl011_shutdown(struct uart_port *port)
 {
 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
+	unsigned int cr;
 
 	/*
 	 * disable all interrupts
@@ -1488,9 +1492,16 @@ static void pl011_shutdown(struct uart_port *port)
 
 	/*
 	 * disable the port
+	 * disable the port. It should not disable RTS and DTR.
+	 * Also RTS and DTR state should be preserved to restore
+	 * it during startup().
 	 */
 	uap->autorts = false;
-	writew(UART01x_CR_UARTEN | UART011_CR_TXE, uap->port.membase + UART011_CR);
+	cr = readw(uap->port.membase + UART011_CR);
+	uap->old_cr = cr;
+	cr &= UART011_CR_RTS | UART011_CR_DTR;
+	cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
+	writew(cr, uap->port.membase + UART011_CR);
 
 	/*
 	 * disable break condition and fifos
@@ -1905,6 +1916,7 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 	uap->vendor = vendor;
 	uap->lcrh_rx = vendor->lcrh_rx;
 	uap->lcrh_tx = vendor->lcrh_tx;
+	uap->old_cr = 0;
 	uap->fifosize = vendor->fifosize;
 	uap->interrupt_may_hang = vendor->interrupt_may_hang;
 	uap->port.dev = &dev->dev;