[PATCH v2] serial: uartlite: Move out-of-range port-numbers into ULITE_NR_UARTS range

[Ruediger Willenberg <r.willenberg@xxxxxxxxxxxxxx>]

Find free uart_port struct in range 0 <= id < ULITE_NR_UARTS when
the device tree port-number property is outside that range. This
happens when there are other UART types in the system because the
Xilinx device tree generator numbers all UARTs consecutively;
as a result, not as many Uartlites as specified by the
SERIAL_UARTLITE_NR_UARTS parameter could be successfully added.

Signed-off-by: Ruediger Willenberg <r.willenberg@xxxxxxxxxxxxxx>
---
Changes in v2:
 - give KERN_NOTICE when changing the id,
   with reference to the requested port-number 

 drivers/tty/serial/uartlite.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index d3d9566e5dbd..27c513c7350e 100644
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -631,15 +631,17 @@ static int ulite_assign(struct device *dev, int id, u32 base, int irq,
 {
 	struct uart_port *port;
 	int rc;
+	int oor_id = -1;
 
-	/* if id = -1; then scan for a free id and use that */
-	if (id < 0) {
+	/* if id -1 or out of range; then scan for a free id and use that */
+	if (id < 0 || id >= ULITE_NR_UARTS) {
+		oor_id = id;
 		for (id = 0; id < ULITE_NR_UARTS; id++)
 			if (ulite_ports[id].mapbase == 0)
 				break;
 	}
-	if (id < 0 || id >= ULITE_NR_UARTS) {
-		dev_err(dev, "%s%i too large\n", ULITE_NAME, id);
+	if (id == ULITE_NR_UARTS) {
+		dev_err(dev, "maximum number of %s assigned\n", ULITE_NAME);
 		return -EINVAL;
 	}
 
@@ -676,7 +678,11 @@ static int ulite_assign(struct device *dev, int id, u32 base, int irq,
 		dev_set_drvdata(dev, NULL);
 		return rc;
 	}
-
+	if (oor_id >= 0)
+		dev_notice(dev,
+			"assigned uartlite with device tree port-number=<%i> to %s%i\n",
+			oor_id, ULITE_NAME, id);
+
 	return 0;
 }
 
-- 
2.25.1