tty: atmel_serial_probe(): index of atmel_ports[] fix

Index of atmel_ports[ATMEL_MAX_UART] should be smaller
than ATMEL_MAX_UART.

Signed-off-by: Pawel Wieczorkiewicz <wpawel@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/atmel_serial.c

@@ -158,7 +158,7 @@ struct atmel_uart_port {
 };
 
 static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
-static unsigned long atmel_ports_in_use;
+static DECLARE_BITMAP(atmel_ports_in_use, ATMEL_MAX_UART);
 
 #ifdef SUPPORT_SYSRQ
 static struct console atmel_console;
@@ -1769,15 +1769,14 @@ static int atmel_serial_probe(struct platform_device *pdev)
 	if (ret < 0)
 		/* port id not found in platform data nor device-tree aliases:
 		 * auto-enumerate it */
-		ret = find_first_zero_bit(&atmel_ports_in_use,
-				sizeof(atmel_ports_in_use));
+		ret = find_first_zero_bit(atmel_ports_in_use, ATMEL_MAX_UART);
 
-	if (ret > ATMEL_MAX_UART) {
+	if (ret >= ATMEL_MAX_UART) {
 		ret = -ENODEV;
 		goto err;
 	}
 
-	if (test_and_set_bit(ret, &atmel_ports_in_use)) {
+	if (test_and_set_bit(ret, atmel_ports_in_use)) {
 		/* port already in use */
 		ret = -EBUSY;
 		goto err;
@@ -1857,7 +1856,7 @@ static int atmel_serial_remove(struct platform_device *pdev)
 
 	/* "port" is allocated statically, so we shouldn't free it */
 
-	clear_bit(port->line, &atmel_ports_in_use);
+	clear_bit(port->line, atmel_ports_in_use);
 
 	clk_put(atmel_port->clk);