1 files changed, 210 insertions, 0 deletions
diff --git a/usb-serial-idr.patch b/usb-serial-idr.patch
new file mode 100644
index 00000000000000..91dbc029c50629
--- /dev/null
+++ b/usb-serial-idr.patch
@@ -0,0 +1,210 @@
+From foo@baz Tue Jun  4 12:06:11 PDT 2013
+Date: Tue, 04 Jun 2013 12:06:11 -0700
+To: Greg KH <gregkh@linuxfoundation.org>
+From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Subject: [PATCH 2/2] USB: serial: make minor allocation dynamic
+
+This moves the allocation of minor device numbers from a static array to
+be dynamic, using the idr interface.  This means that you could
+potentially get "gaps" in a minor number range for a single USB serial
+device with multiple ports, but all should still work properly.
+
+Note, we still have the limitation of 255 USB to serial devices in the
+system, as that is all we are registering with the TTY layer at this
+point in time.
+
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/usb/serial/usb-serial.c |   97 ++++++++++++++++++++--------------------
+ include/linux/usb/serial.h      |    4 -
+ 2 files changed, 51 insertions(+), 50 deletions(-)
+
+--- a/drivers/usb/serial/usb-serial.c
++++ b/drivers/usb/serial/usb-serial.c
+@@ -37,6 +37,7 @@
+ #include <linux/usb.h>
+ #include <linux/usb/serial.h>
+ #include <linux/kfifo.h>
++#include <linux/idr.h>
+ #include "pl2303.h"
+ 
+ #define DRIVER_AUTHOR "Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
+@@ -49,7 +50,7 @@
+    drivers depend on it.
+ */
+ 
+-static struct usb_serial *serial_table[SERIAL_TTY_MINORS];
++static DEFINE_IDR(serial_minors);
+ static DEFINE_MUTEX(table_lock);
+ static LIST_HEAD(usb_serial_driver_list);
+ 
+@@ -60,61 +61,65 @@ static LIST_HEAD(usb_serial_driver_list)
+  */
+ struct usb_serial *usb_serial_get_by_index(unsigned index)
+ {
+-	struct usb_serial *serial;
++	struct usb_serial *serial = NULL;
++	struct usb_serial_port *port;
+ 
+ 	mutex_lock(&table_lock);
+-	serial = serial_table[index];
++	port = idr_find(&serial_minors, index);
++	if (!port)
++		goto exit;
+ 
+-	if (serial) {
+-		mutex_lock(&serial->disc_mutex);
+-		if (serial->disconnected) {
+-			mutex_unlock(&serial->disc_mutex);
+-			serial = NULL;
+-		} else {
+-			kref_get(&serial->kref);
+-		}
++	serial = port->serial;
++	mutex_lock(&serial->disc_mutex);
++	if (serial->disconnected) {
++		mutex_unlock(&serial->disc_mutex);
++		serial = NULL;
++	} else {
++		kref_get(&serial->kref);
+ 	}
+ 	mutex_unlock(&table_lock);
++exit:
+ 	return serial;
+ }
+ 
+-static struct usb_serial *get_free_serial(struct usb_serial *serial,
+-					int num_ports, unsigned int *minor)
++static int get_free_port(struct usb_serial_port *port)
+ {
+-	unsigned int i, j;
+-	int good_spot;
+-
+-	dev_dbg(&serial->interface->dev, "%s %d\n", __func__, num_ports);
++	int i;
+ 
+-	*minor = 0;
+ 	mutex_lock(&table_lock);
+-	for (i = 0; i < SERIAL_TTY_MINORS; ++i) {
+-		if (serial_table[i])
+-			continue;
++	i = idr_alloc(&serial_minors, port, 0, 0, GFP_KERNEL);
++	if (i < 0)
++		goto exit;
++	port->minor = i;
++exit:
++	mutex_unlock(&table_lock);
++	return i;
++}
+ 
+-		good_spot = 1;
+-		for (j = 1; j <= num_ports-1; ++j)
+-			if ((i+j >= SERIAL_TTY_MINORS) || (serial_table[i+j])) {
+-				good_spot = 0;
+-				i += j;
+-				break;
+-			}
+-		if (good_spot == 0)
+-			continue;
++static int get_free_serial(struct usb_serial *serial, int num_ports,
++			   unsigned int *minor)
++{
++	unsigned int i;
++	unsigned int j;
++	int x;
+ 
+-		*minor = i;
+-		j = 0;
+-		dev_dbg(&serial->interface->dev, "%s - minor base = %d\n", __func__, *minor);
+-		for (i = *minor; (i < (*minor + num_ports)) && (i < SERIAL_TTY_MINORS); ++i, ++j) {
+-			serial_table[i] = serial;
+-			serial->port[j]->minor = i;
+-			serial->port[j]->port_number = i - *minor;
+-		}
+-		mutex_unlock(&table_lock);
+-		return serial;
++	dev_dbg(&serial->interface->dev, "%s %d\n", __func__, num_ports);
++
++	*minor = 0xffffffff;
++	for (i = 0; i < num_ports; ++i) {
++		x = get_free_port(serial->port[i]);
++		if (x < 0)
++			goto error;
++		if (*minor == 0xffffffff)
++			*minor = x;
++		serial->port[i]->port_number = i;
+ 	}
+-	mutex_unlock(&table_lock);
+-	return NULL;
++	return 0;
++error:
++	/* unwind the already allocated minors */
++	for (j = 0; j < i; ++j)
++		idr_remove(&serial_minors, serial->port[j]->port_number);
++	return x;
+ }
+ 
+ static void return_serial(struct usb_serial *serial)
+@@ -123,7 +128,7 @@ static void return_serial(struct usb_ser
+ 
+ 	mutex_lock(&table_lock);
+ 	for (i = 0; i < serial->num_ports; ++i)
+-		serial_table[serial->minor + i] = NULL;
++		idr_remove(&serial_minors, serial->port[i]->port_number);
+ 	mutex_unlock(&table_lock);
+ }
+ 
+@@ -1042,7 +1047,7 @@ static int usb_serial_probe(struct usb_i
+ 	 */
+ 	serial->disconnected = 1;
+ 
+-	if (get_free_serial(serial, num_ports, &minor) == NULL) {
++	if (get_free_serial(serial, num_ports, &minor)) {
+ 		dev_err(ddev, "No more free serial devices\n");
+ 		goto probe_error;
+ 	}
+@@ -1226,7 +1231,6 @@ static struct usb_driver usb_serial_driv
+ 
+ static int __init usb_serial_init(void)
+ {
+-	int i;
+ 	int result;
+ 
+ 	usb_serial_tty_driver = alloc_tty_driver(SERIAL_TTY_MINORS);
+@@ -1234,9 +1238,6 @@ static int __init usb_serial_init(void)
+ 		return -ENOMEM;
+ 
+ 	/* Initialize our global data */
+-	for (i = 0; i < SERIAL_TTY_MINORS; ++i)
+-		serial_table[i] = NULL;
+-
+ 	result = bus_register(&usb_serial_bus_type);
+ 	if (result) {
+ 		pr_err("%s - registering bus driver failed\n", __func__);
+--- a/include/linux/usb/serial.h
++++ b/include/linux/usb/serial.h
+@@ -21,7 +21,7 @@
+ 
+ #define SERIAL_TTY_MAJOR	188	/* Nice legal number now */
+ #define SERIAL_TTY_MINORS	254	/* loads of devices :) */
+-#define SERIAL_TTY_NO_MINOR	255	/* No minor was assigned */
++#define SERIAL_TTY_NO_MINOR	0xffffffff	/* No minor was assigned */
+ 
+ /* The maximum number of ports one device can grab at once */
+ #define MAX_NUM_PORTS		8
+@@ -161,13 +161,13 @@ struct usb_serial {
+ 	unsigned char			disconnected:1;
+ 	unsigned char			suspending:1;
+ 	unsigned char			attached:1;
+-	unsigned char			minor;
+ 	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;
++	u32				minor;
+ 	struct usb_serial_port		*port[MAX_NUM_PORTS];
+ 	struct kref			kref;
+ 	struct mutex			disc_mutex;