1 files changed, 31 insertions, 4 deletions

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 6fcdb90f616a..aff04f1de3a5 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -121,25 +121,44 @@ static void dw8250_check_lcr(struct uart_port *p, int value)
 }
 
 /* Returns once the transmitter is empty or we run out of retries */
-static void dw8250_tx_wait_empty(struct uart_port *p, int tries)
+static void dw8250_tx_wait_empty(struct uart_port *p)
 {
+	unsigned int tries = 20000;
+	unsigned int delay_threshold = tries - 1000;
 	unsigned int lsr;
 
 	while (tries--) {
 		lsr = readb (p->membase + (UART_LSR << p->regshift));
 		if (lsr & UART_LSR_TEMT)
 			break;
-		udelay (10);
+
+		/* The device is first given a chance to empty without delay,
+		 * to avoid slowdowns at high bitrates. If after 1000 tries
+		 * the buffer has still not emptied, allow more time for low-
+		 * speed links. */
+		if (tries < delay_threshold)
+			udelay (1);
 	}
 }
 
-static void dw8250_serial_out(struct uart_port *p, int offset, int value)
+static void dw8250_serial_out38x(struct uart_port *p, int offset, int value)
 {
 	struct dw8250_data *d = p->private_data;
 
 	/* Allow the TX to drain before we reconfigure */
 	if (offset == UART_LCR)
-		dw8250_tx_wait_empty(p, 1000);
+		dw8250_tx_wait_empty(p);
+
+	writeb(value, p->membase + (offset << p->regshift));
+
+	if (offset == UART_LCR && !d->uart_16550_compatible)
+		dw8250_check_lcr(p, value);
+}
+
+
+static void dw8250_serial_out(struct uart_port *p, int offset, int value)
+{
+	struct dw8250_data *d = p->private_data;
 
 	writeb(value, p->membase + (offset << p->regshift));
 
@@ -357,6 +376,9 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
 			p->serial_in = dw8250_serial_in32be;
 			p->serial_out = dw8250_serial_out32be;
 		}
+		if (of_device_is_compatible(np, "marvell,armada-38x-uart"))
+			p->serial_out = dw8250_serial_out38x;
+
 	} else if (acpi_dev_present("APMC0D08", NULL, -1)) {
 		p->iotype = UPIO_MEM32;
 		p->regshift = 2;
@@ -554,6 +576,10 @@ static int dw8250_probe(struct platform_device *pdev)
 	if (!data->skip_autocfg)
 		dw8250_setup_port(p);
 
+#ifdef CONFIG_PM
+	uart.capabilities |= UART_CAP_RPM;
+#endif
+
 	/* If we have a valid fifosize, try hooking up DMA */
 	if (p->fifosize) {
 		data->dma.rxconf.src_maxburst = p->fifosize / 4;
@@ -666,6 +692,7 @@ static const struct dev_pm_ops dw8250_pm_ops = {
 static const struct of_device_id dw8250_of_match[] = {
 	{ .compatible = "snps,dw-apb-uart" },
 	{ .compatible = "cavium,octeon-3860-uart" },
+	{ .compatible = "marvell,armada-38x-uart" },
 	{ /* Sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, dw8250_of_match);