USB: serial: clean up endpoint and port-counter types

Use unsigned-char type for the endpoint and port counters.
Signed-off-by: Johan Hovold <johan@kernel.org>

drivers/usb/serial/usb-serial.c

@@ -728,12 +728,12 @@ static int usb_serial_probe(struct usb_interface *interface,
 	int buffer_size;
 	int i;
 	int j;
-	int num_interrupt_in = 0;
-	int num_interrupt_out = 0;
-	int num_bulk_in = 0;
-	int num_bulk_out = 0;
+	unsigned char num_interrupt_in = 0;
+	unsigned char num_interrupt_out = 0;
+	unsigned char num_bulk_in = 0;
+	unsigned char num_bulk_out = 0;
 	int num_ports = 0;
-	int max_endpoints;
+	unsigned char max_endpoints;
 
 	mutex_lock(&table_lock);
 	type = search_serial_device(interface);
@@ -879,7 +879,7 @@ static int usb_serial_probe(struct usb_interface *interface,
 		num_ports = MAX_NUM_PORTS;
 	}
 
-	serial->num_ports = num_ports;
+	serial->num_ports = (unsigned char)num_ports;
 	serial->num_bulk_in = num_bulk_in;
 	serial->num_bulk_out = num_bulk_out;
 	serial->num_interrupt_in = num_interrupt_in;
@@ -894,7 +894,7 @@ static int usb_serial_probe(struct usb_interface *interface,
 	max_endpoints = max(num_bulk_in, num_bulk_out);
 	max_endpoints = max(max_endpoints, num_interrupt_in);
 	max_endpoints = max(max_endpoints, num_interrupt_out);
-	max_endpoints = max(max_endpoints, (int)serial->num_ports);
+	max_endpoints = max(max_endpoints, serial->num_ports);
 	serial->num_port_pointers = max_endpoints;
 
 	dev_dbg(ddev, "setting up %d port structure(s)\n", max_endpoints);

include/linux/usb/serial.h

@@ -159,10 +159,10 @@ struct usb_serial {
 	unsigned char			minors_reserved:1;
 	unsigned char			num_ports;
 	unsigned char			num_port_pointers;
-	char				num_interrupt_in;
-	char				num_interrupt_out;
-	char				num_bulk_in;
-	char				num_bulk_out;
+	unsigned char			num_interrupt_in;
+	unsigned char			num_interrupt_out;
+	unsigned char			num_bulk_in;
+	unsigned char			num_bulk_out;
 	struct usb_serial_port		*port[MAX_NUM_PORTS];
 	struct kref			kref;
 	struct mutex			disc_mutex;
@@ -227,13 +227,14 @@ static inline void usb_set_serial_data(struct usb_serial *serial, void *data)
 struct usb_serial_driver {
 	const char *description;
 	const struct usb_device_id *id_table;
-	char	num_ports;
 
 	struct list_head	driver_list;
 	struct device_driver	driver;
 	struct usb_driver	*usb_driver;
 	struct usb_dynids	dynids;
 
+	unsigned char		num_ports;
+
 	size_t			bulk_in_size;
 	size_t			bulk_out_size;