[PATCH 0/3] Increase the number of USB to serial devices we can support at once

[PATCH 0/3] Increase the number of USB to serial devices we can support at once

[Greg KH]

Here are 3 patches that I've tested out on my system with only a small
number of devices, but it seems to work, so why not let others try it
out...

These patches make the USB to serial core have the ability to support up
to 3000 devices at once now.  We do this in the following steps:
	- adding the minor number to the usb_serial_port structure
	- removing the static array of ports, and use idr instead
	- increasing the number

Now, if you pay attention, we end up taking up more runtime memory than
before, because we are asking the tty layer to reserve a bunch more tty
devices for us, negating the potential savings of getting rid of our
original static array.  I'll work on fixing up the tty layer calls to
properly allocate the tty devices only when we need them, much like the
pty layer does.  When that's done, we can bump the number of usb to
serial devices up to 16k with no memory problems.

This series is based on my usb-linus branch on my usb.git tree on
git.kernel.org, as I needed some of the usb-serial fixes that are in
that branch already.

Testing / review is most welcome.

thanks,

greg k-h

[PATCH 2/3] USB: serial: make minor allocation dynamic

[Greg KH]

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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);
 	}
+exit:
 	mutex_unlock(&table_lock);
 	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]->minor);
+	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]->minor);
 	mutex_unlock(&table_lock);
 }
 
@@ -1040,7 +1045,7 @@ 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;
 	}
@@ -1224,7 +1229,6 @@ 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);
@@ -1232,9 +1236,6 @@ 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;

[PATCH 3/3] USB: serial: increase the number of devices we support

[Greg KH]

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We had the limit of 255 USB to serial devices on one system for almost
15 years, with no complaints.  But now it's time to move on from these
tiny "baby" systems, and bump the number up to 3000, which should last
us a few more years.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/serial/usb-serial.c |    8 ++++++--
 include/linux/usb/serial.h      |    4 ----
 2 files changed, 6 insertions(+), 6 deletions(-)

--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -43,6 +43,10 @@
 #define DRIVER_AUTHOR "Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
 #define DRIVER_DESC "USB Serial Driver core"
 
+#define SERIAL_TTY_MAJOR	188
+#define SERIAL_TTY_MINORS	3000	/* should be enough for a while */
+#define SERIAL_TTY_NO_MINOR	(SERIAL_TTY_MINORS + 1)
+
 /* There is no MODULE_DEVICE_TABLE for usbserial.c.  Instead
    the MODULE_DEVICE_TABLE declarations in each serial driver
    cause the "hotplug" program to pull in whatever module is necessary
@@ -105,12 +109,12 @@ static int get_free_serial(struct usb_se
 
 	dev_dbg(&serial->interface->dev, "%s %d\n", __func__, num_ports);
 
-	*minor = 0xffffffff;
+	*minor = SERIAL_TTY_NO_MINOR;
 	for (i = 0; i < num_ports; ++i) {
 		x = get_free_port(serial->port[i]);
 		if (x < 0)
 			goto error;
-		if (*minor == 0xffffffff)
+		if (*minor == SERIAL_TTY_NO_MINOR)
 			*minor = x;
 		serial->port[i]->port_number = i;
 	}
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -19,10 +19,6 @@
 #include <linux/sysrq.h>
 #include <linux/kfifo.h>
 
-#define SERIAL_TTY_MAJOR	188	/* Nice legal number now */
-#define SERIAL_TTY_MINORS	254	/* loads of devices :) */
-#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
 

[PATCH 1/3] USB: serial: ports: add minor and port number

[Greg KH]

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The usb_serial_port structure had the number field, which was the minor
number for the port, which almost no one really cared about.  They
really wanted the number of the port within the device, which you had to
subtract from the minor of the parent usb_serial_device structure.  To
clean this up, provide the real minor number of the port, and the number
of the port within the serial device separately, as these numbers might
not be related in the future.

Bonus is that this cleans up a lot of logic in the drivers, and saves
lines overall.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

--
 drivers/staging/serqt_usb2/serqt_usb2.c |   21 +++--------
 drivers/usb/serial/ark3116.c            |    2 -
 drivers/usb/serial/bus.c                |    6 +--
 drivers/usb/serial/console.c            |    2 -
 drivers/usb/serial/cp210x.c             |    2 -
 drivers/usb/serial/cypress_m8.c         |    4 +-
 drivers/usb/serial/digi_acceleport.c    |    6 ---
 drivers/usb/serial/f81232.c             |    5 +-
 drivers/usb/serial/garmin_gps.c         |    6 +--
 drivers/usb/serial/io_edgeport.c        |   60 ++++++++++++--------------------
 drivers/usb/serial/io_ti.c              |   21 ++++-------
 drivers/usb/serial/keyspan.c            |   29 ++++++---------
 drivers/usb/serial/metro-usb.c          |    4 +-
 drivers/usb/serial/mos7720.c            |   37 +++++++++----------
 drivers/usb/serial/mos7840.c            |   52 +++++++++------------------
 drivers/usb/serial/opticon.c            |    2 -
 drivers/usb/serial/pl2303.c             |    2 -
 drivers/usb/serial/quatech2.c           |    7 +--
 drivers/usb/serial/sierra.c             |    2 -
 drivers/usb/serial/ti_usb_3410_5052.c   |   10 ++---
 drivers/usb/serial/usb-serial.c         |    7 ++-
 drivers/usb/serial/usb_wwan.c           |    2 -
 drivers/usb/serial/whiteheat.c          |   20 +++++-----
 include/linux/usb/serial.h              |    6 ++-
 24 files changed, 134 insertions(+), 181 deletions(-)

--- a/drivers/staging/serqt_usb2/serqt_usb2.c
+++ b/drivers/staging/serqt_usb2/serqt_usb2.c
@@ -873,7 +873,7 @@ static int qt_open(struct tty_struct *tt
 	result = qt_get_device(serial, &port0->DeviceData);
 
 	/* Port specific setups */
-	result = qt_open_channel(serial, port->number, &ChannelData);
+	result = qt_open_channel(serial, port->port_number, &ChannelData);
 	if (result < 0) {
 		dev_dbg(&port->dev, "qt_open_channel failed\n");
 		return result;
@@ -888,7 +888,7 @@ static int qt_open(struct tty_struct *tt
 	    (SERIAL_MSR_CTS | SERIAL_MSR_DSR | SERIAL_MSR_RI | SERIAL_MSR_CD);
 
 	/* Set Baud rate to default and turn off (default)flow control here */
-	result = qt_setuart(serial, port->number, DEFAULT_DIVISOR, DEFAULT_LCR);
+	result = qt_setuart(serial, port->port_number, DEFAULT_DIVISOR, DEFAULT_LCR);
 	if (result < 0) {
 		dev_dbg(&port->dev, "qt_setuart failed\n");
 		return result;
@@ -906,7 +906,6 @@ static int qt_open(struct tty_struct *tt
 			qt_submit_urb_from_open(serial, port);
 	}
 
-	dev_dbg(&port->dev, "port number is %d\n", port->number);
 	dev_dbg(&port->dev, "serial number is %d\n", port->serial->minor);
 	dev_dbg(&port->dev,
 		"Bulkin endpoint is %d\n", port->bulk_in_endpointAddress);
@@ -1022,14 +1021,11 @@ static void qt_close(struct usb_serial_p
 	/* Close uart channel */
 	status = qt_close_channel(serial, index);
 	if (status < 0)
-		dev_dbg(&port->dev,
-			"%s - port %d qt_close_channel failed.\n",
-			__func__, port->number);
+		dev_dbg(&port->dev, "%s - qt_close_channel failed.\n", __func__);
 
 	port0->open_ports--;
 
-	dev_dbg(&port->dev, "qt_num_open_ports in close%d:in port%d\n",
-		port0->open_ports, port->number);
+	dev_dbg(&port->dev, "qt_num_open_ports in close%d\n", port0->open_ports);
 
 	if (port0->open_ports == 0) {
 		if (serial->port[0]->interrupt_in_urb) {
@@ -1169,8 +1165,7 @@ static int qt_ioctl(struct tty_struct *t
 		return 0;
 	}
 
-	dev_dbg(&port->dev, "%s -No ioctl for that one.  port = %d\n",
-		__func__, port->number);
+	dev_dbg(&port->dev, "%s -No ioctl for that one.\n", __func__);
 	return -ENOIOCTLCMD;
 }
 
@@ -1245,8 +1240,7 @@ static void qt_set_termios(struct tty_st
 
 	/* Now determine flow control */
 	if (cflag & CRTSCTS) {
-		dev_dbg(&port->dev, "%s - Enabling HW flow control port %d\n",
-			__func__, port->number);
+		dev_dbg(&port->dev, "%s - Enabling HW flow control\n", __func__);
 
 		/* Enable RTS/CTS flow control */
 		status = BoxSetHW_FlowCtrl(port->serial, index, 1);
@@ -1258,8 +1252,7 @@ static void qt_set_termios(struct tty_st
 	} else {
 		/* Disable RTS/CTS flow control */
 		dev_dbg(&port->dev,
-			"%s - disabling HW flow control port %d\n",
-			__func__, port->number);
+			"%s - disabling HW flow control\n", __func__);
 
 		status = BoxSetHW_FlowCtrl(port->serial, index, 0);
 		if (status < 0) {
--- a/drivers/usb/serial/ark3116.c
+++ b/drivers/usb/serial/ark3116.c
@@ -414,7 +414,7 @@ static int ark3116_ioctl(struct tty_stru
 		memset(&serstruct, 0, sizeof(serstruct));
 		serstruct.type = PORT_16654;
 		serstruct.line = port->serial->minor;
-		serstruct.port = port->number;
+		serstruct.port = port->port_number;
 		serstruct.custom_divisor = 0;
 		serstruct.baud_base = 460800;
 
--- a/drivers/usb/serial/bus.c
+++ b/drivers/usb/serial/bus.c
@@ -43,7 +43,7 @@ static ssize_t show_port_number(struct d
 {
 	struct usb_serial_port *port = to_usb_serial_port(dev);
 
-	return sprintf(buf, "%d\n", port->number - port->serial->minor);
+	return sprintf(buf, "%d\n", port->port_number);
 }
 
 static DEVICE_ATTR(port_number, S_IRUGO, show_port_number, NULL);
@@ -80,7 +80,7 @@ static int usb_serial_device_probe(struc
 		goto exit_with_autopm;
 	}
 
-	minor = port->number;
+	minor = port->minor;
 	tty_register_device(usb_serial_tty_driver, minor, dev);
 	dev_info(&port->serial->dev->dev,
 		 "%s converter now attached to ttyUSB%d\n",
@@ -106,7 +106,7 @@ static int usb_serial_device_remove(stru
 	/* make sure suspend/resume doesn't race against port_remove */
 	usb_autopm_get_interface(port->serial->interface);
 
-	minor = port->number;
+	minor = port->minor;
 	tty_unregister_device(usb_serial_tty_driver, minor);
 
 	device_remove_file(&port->dev, &dev_attr_port_number);
--- a/drivers/usb/serial/console.c
+++ b/drivers/usb/serial/console.c
@@ -210,7 +210,7 @@ static void usb_console_write(struct con
 	if (count == 0)
 		return;
 
-	pr_debug("%s - port %d, %d byte(s)\n", __func__, port->number, count);
+	pr_debug("%s - minor %d, %d byte(s)\n", __func__, port->minor, count);
 
 	if (!port->port.console) {
 		pr_debug("%s - port not opened\n", __func__);
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -666,8 +666,6 @@ static void cp210x_set_termios(struct tt
 	unsigned int bits;
 	unsigned int modem_ctl[4];
 
-	dev_dbg(dev, "%s - port %d\n", __func__, port->number);
-
 	if (!tty)
 		return;
 
--- a/drivers/usb/serial/cypress_m8.c
+++ b/drivers/usb/serial/cypress_m8.c
@@ -435,7 +435,7 @@ static void cypress_set_dead(struct usb_
 	spin_unlock_irqrestore(&priv->lock, flags);
 
 	dev_err(&port->dev, "cypress_m8 suspending failing port %d - "
-		"interval might be too short\n", port->number);
+		"interval might be too short\n", port->port_number);
 }
 
 
@@ -667,7 +667,7 @@ static int cypress_write(struct tty_stru
 {
 	struct cypress_private *priv = usb_get_serial_port_data(port);
 
-	dev_dbg(&port->dev, "%s - port %d, %d bytes\n", __func__, port->number, count);
+	dev_dbg(&port->dev, "%s - %d bytes\n", __func__, count);
 
 	/* line control commands, which need to be executed immediately,
 	   are not put into the buffer for obvious reasons.
--- a/drivers/usb/serial/digi_acceleport.c
+++ b/drivers/usb/serial/digi_acceleport.c
@@ -1304,11 +1304,7 @@ static void digi_release(struct usb_seri
 
 static int digi_port_probe(struct usb_serial_port *port)
 {
-	unsigned port_num;
-
-	port_num = port->number - port->serial->minor;
-
-	return digi_port_init(port, port_num);
+	return digi_port_init(port, port->port_number);
 }
 
 static int digi_port_remove(struct usb_serial_port *port)
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -288,15 +288,14 @@ static int f81232_ioctl(struct tty_struc
 	struct serial_struct ser;
 	struct usb_serial_port *port = tty->driver_data;
 
-	dev_dbg(&port->dev, "%s (%d) cmd = 0x%04x\n", __func__,
-		port->number, cmd);
+	dev_dbg(&port->dev, "%s cmd = 0x%04x\n", __func__, cmd);
 
 	switch (cmd) {
 	case TIOCGSERIAL:
 		memset(&ser, 0, sizeof ser);
 		ser.type = PORT_16654;
 		ser.line = port->serial->minor;
-		ser.port = port->number;
+		ser.port = port->port_number;
 		ser.baud_base = 460800;
 
 		if (copy_to_user((void __user *)arg, &ser, sizeof ser))
--- a/drivers/usb/serial/garmin_gps.c
+++ b/drivers/usb/serial/garmin_gps.c
@@ -948,9 +948,9 @@ static void garmin_close(struct usb_seri
 {
 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
 
-	dev_dbg(&port->dev, "%s - port %d - mode=%d state=%d flags=0x%X\n",
-		__func__, port->number, garmin_data_p->mode,
-		garmin_data_p->state, garmin_data_p->flags);
+	dev_dbg(&port->dev, "%s - mode=%d state=%d flags=0x%X\n",
+		__func__, garmin_data_p->mode, garmin_data_p->state,
+		garmin_data_p->flags);
 
 	garmin_clear(garmin_data_p);
 
--- a/drivers/usb/serial/io_edgeport.c
+++ b/drivers/usb/serial/io_edgeport.c
@@ -915,8 +915,8 @@ static int edge_open(struct tty_struct *
 		return -ENOMEM;
 	}
 
-	dev_dbg(dev, "%s(%d) - Initialize TX fifo to %d bytes\n",
-		__func__, port->number, edge_port->maxTxCredits);
+	dev_dbg(dev, "%s - Initialize TX fifo to %d bytes\n",
+		__func__, edge_port->maxTxCredits);
 
 	return 0;
 }
@@ -1122,9 +1122,8 @@ static int edge_write(struct tty_struct
 	copySize = min((unsigned int)count,
 				(edge_port->txCredits - fifo->count));
 
-	dev_dbg(&port->dev, "%s(%d) of %d byte(s) Fifo room  %d -- will copy %d bytes\n",
-		__func__, port->number, count,
-			edge_port->txCredits - fifo->count, copySize);
+	dev_dbg(&port->dev, "%s of %d byte(s) Fifo room  %d -- will copy %d bytes\n",
+		__func__, count, edge_port->txCredits - fifo->count, copySize);
 
 	/* catch writes of 0 bytes which the tty driver likes to give us,
 	   and when txCredits is empty */
@@ -1216,9 +1215,8 @@ static void send_more_port_data(struct e
 	if (edge_port->write_in_progress ||
 	    !edge_port->open             ||
 	    (fifo->count == 0)) {
-		dev_dbg(dev, "%s(%d) EXIT - fifo %d, PendingWrite = %d\n",
-			__func__, edge_port->port->number,
-			fifo->count, edge_port->write_in_progress);
+		dev_dbg(dev, "%s EXIT - fifo %d, PendingWrite = %d\n",
+			__func__, fifo->count, edge_port->write_in_progress);
 		goto exit_send;
 	}
 
@@ -1230,9 +1228,8 @@ static void send_more_port_data(struct e
 	 * it's better to wait for more credits so we can do a larger write.
 	 */
 	if (edge_port->txCredits < EDGE_FW_GET_TX_CREDITS_SEND_THRESHOLD(edge_port->maxTxCredits, EDGE_FW_BULK_MAX_PACKET_SIZE)) {
-		dev_dbg(dev, "%s(%d) Not enough credit - fifo %d TxCredit %d\n",
-			__func__, edge_port->port->number, fifo->count,
-			edge_port->txCredits);
+		dev_dbg(dev, "%s Not enough credit - fifo %d TxCredit %d\n",
+			__func__, fifo->count, edge_port->txCredits);
 		goto exit_send;
 	}
 
@@ -1256,10 +1253,8 @@ static void send_more_port_data(struct e
 		edge_port->write_in_progress = false;
 		goto exit_send;
 	}
-	buffer[0] = IOSP_BUILD_DATA_HDR1(edge_port->port->number
-				- edge_port->port->serial->minor, count);
-	buffer[1] = IOSP_BUILD_DATA_HDR2(edge_port->port->number
-				- edge_port->port->serial->minor, count);
+	buffer[0] = IOSP_BUILD_DATA_HDR1(edge_port->port->port_number, count);
+	buffer[1] = IOSP_BUILD_DATA_HDR2(edge_port->port->port_number, count);
 
 	/* now copy our data */
 	bytesleft =  fifo->size - fifo->tail;
@@ -1377,8 +1372,7 @@ static int edge_chars_in_buffer(struct t
 						edge_port->txfifo.count;
 	spin_unlock_irqrestore(&edge_port->ep_lock, flags);
 	if (num_chars) {
-		dev_dbg(&port->dev, "%s(port %d) - returns %d\n", __func__,
-			port->number, num_chars);
+		dev_dbg(&port->dev, "%s - returns %d\n", __func__, num_chars);
 	}
 
 	return num_chars;
@@ -1576,7 +1570,7 @@ static int get_serial_info(struct edgepo
 
 	tmp.type		= PORT_16550A;
 	tmp.line		= edge_port->port->serial->minor;
-	tmp.port		= edge_port->port->number;
+	tmp.port		= edge_port->port->port_number;
 	tmp.irq			= 0;
 	tmp.flags		= ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 	tmp.xmit_fifo_size	= edge_port->maxTxCredits;
@@ -1601,15 +1595,15 @@ static int edge_ioctl(struct tty_struct
 	DEFINE_WAIT(wait);
 	struct edgeport_port *edge_port = usb_get_serial_port_data(port);
 
-	dev_dbg(&port->dev, "%s - port %d, cmd = 0x%x\n", __func__, port->number, cmd);
+	dev_dbg(&port->dev, "%s - cmd = 0x%x\n", __func__, cmd);
 
 	switch (cmd) {
 	case TIOCSERGETLSR:
-		dev_dbg(&port->dev, "%s (%d) TIOCSERGETLSR\n", __func__,  port->number);
+		dev_dbg(&port->dev, "%s TIOCSERGETLSR\n", __func__);
 		return get_lsr_info(edge_port, (unsigned int __user *) arg);
 
 	case TIOCGSERIAL:
-		dev_dbg(&port->dev, "%s (%d) TIOCGSERIAL\n", __func__,  port->number);
+		dev_dbg(&port->dev, "%s TIOCGSERIAL\n", __func__);
 		return get_serial_info(edge_port, (struct serial_struct __user *) arg);
 	}
 	return -ENOIOCTLCMD;
@@ -2181,9 +2175,8 @@ static int send_iosp_ext_cmd(struct edge
 
 	currentCommand = buffer;
 
-	MAKE_CMD_EXT_CMD(&currentCommand, &length,
-		edge_port->port->number - edge_port->port->serial->minor,
-		command, param);
+	MAKE_CMD_EXT_CMD(&currentCommand, &length, edge_port->port->port_number,
+			 command, param);
 
 	status = write_cmd_usb(edge_port, buffer, length);
 	if (status) {
@@ -2266,18 +2259,16 @@ static int send_cmd_write_baud_rate(stru
 	int cmdLen = 0;
 	int divisor;
 	int status;
-	unsigned char number =
-		edge_port->port->number - edge_port->port->serial->minor;
+	u32 number = edge_port->port->port_number;
 
 	if (edge_serial->is_epic &&
 	    !edge_serial->epic_descriptor.Supports.IOSPSetBaudRate) {
-		dev_dbg(dev, "SendCmdWriteBaudRate - NOT Setting baud rate for port = %d, baud = %d\n",
-			edge_port->port->number, baudRate);
+		dev_dbg(dev, "SendCmdWriteBaudRate - NOT Setting baud rate for port, baud = %d\n",
+			baudRate);
 		return 0;
 	}
 
-	dev_dbg(dev, "%s - port = %d, baud = %d\n", __func__,
-		edge_port->port->number, baudRate);
+	dev_dbg(dev, "%s - baud = %d\n", __func__, baudRate);
 
 	status = calc_baud_rate_divisor(dev, baudRate, &divisor);
 	if (status) {
@@ -2302,7 +2293,7 @@ static int send_cmd_write_baud_rate(stru
 
 	/* Restore original value to disable access to divisor latch */
 	MAKE_CMD_WRITE_REG(&currCmd, &cmdLen, number, LCR,
-						edge_port->shadowLCR);
+			   edge_port->shadowLCR);
 
 	status = write_cmd_usb(edge_port, cmdBuffer, cmdLen);
 	if (status) {
@@ -2388,9 +2379,8 @@ static int send_cmd_write_uart_register(
 	currCmd = cmdBuffer;
 
 	/* Build a cmd in the buffer to write the given register */
-	MAKE_CMD_WRITE_REG(&currCmd, &cmdLen,
-		edge_port->port->number - edge_port->port->serial->minor,
-		regNum, regValue);
+	MAKE_CMD_WRITE_REG(&currCmd, &cmdLen, edge_port->port->port_number,
+			   regNum, regValue);
 
 	status = write_cmd_usb(edge_port, cmdBuffer, cmdLen);
 	if (status) {
@@ -2424,8 +2414,6 @@ static void change_port_settings(struct
 	__u8 txFlow;
 	int status;
 
-	dev_dbg(dev, "%s - port %d\n", __func__, edge_port->port->number);
-
 	if (!edge_port->open &&
 	    !edge_port->openPending) {
 		dev_dbg(dev, "%s - port not opened\n", __func__);
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -259,7 +259,7 @@ static int send_cmd(struct usb_device *d
 /* clear tx/rx buffers and fifo in TI UMP */
 static int purge_port(struct usb_serial_port *port, __u16 mask)
 {
-	int port_number = port->number - port->serial->minor;
+	int port_number = port->port_number;
 
 	dev_dbg(&port->dev, "%s - port %d, mask %x\n", __func__, port_number, mask);
 
@@ -1392,7 +1392,8 @@ stayinbootmode:
 
 static int ti_do_config(struct edgeport_port *port, int feature, int on)
 {
-	int port_number = port->port->number - port->port->serial->minor;
+	int port_number = port->port->port_number;
+
 	on = !!on;	/* 1 or 0 not bitmask */
 	return send_cmd(port->port->serial->dev,
 			feature, (__u8)(UMPM_UART1_PORT + port_number),
@@ -1637,7 +1638,7 @@ static void edge_bulk_in_callback(struct
 		return;
 	}
 
-	port_number = edge_port->port->number - edge_port->port->serial->minor;
+	port_number = edge_port->port->port_number;
 
 	if (edge_port->lsr_event) {
 		edge_port->lsr_event = 0;
@@ -1730,7 +1731,7 @@ static int edge_open(struct tty_struct *
 	if (edge_port == NULL)
 		return -ENODEV;
 
-	port_number = port->number - port->serial->minor;
+	port_number = port->port_number;
 	switch (port_number) {
 	case 0:
 		edge_port->uart_base = UMPMEM_BASE_UART1;
@@ -1908,7 +1909,7 @@ static void edge_close(struct usb_serial
 	spin_unlock_irqrestore(&edge_port->ep_lock, flags);
 
 	dev_dbg(&port->dev, "%s - send umpc_close_port\n", __func__);
-	port_number = port->number - port->serial->minor;
+	port_number = port->port_number;
 	send_cmd(serial->dev, UMPC_CLOSE_PORT,
 		     (__u8)(UMPM_UART1_PORT + port_number), 0, NULL, 0);
 
@@ -2137,10 +2138,7 @@ static void change_port_settings(struct
 	int baud;
 	unsigned cflag;
 	int status;
-	int port_number = edge_port->port->number -
-					edge_port->port->serial->minor;
-
-	dev_dbg(dev, "%s - port %d\n", __func__, edge_port->port->number);
+	int port_number = edge_port->port->port_number;
 
 	config = kmalloc (sizeof (*config), GFP_KERNEL);
 	if (!config) {
@@ -2284,7 +2282,6 @@ static void edge_set_termios(struct tty_
 		tty->termios.c_cflag, tty->termios.c_iflag);
 	dev_dbg(&port->dev, "%s - old clfag %08x old iflag %08x\n", __func__,
 		old_termios->c_cflag, old_termios->c_iflag);
-	dev_dbg(&port->dev, "%s - port %d\n", __func__, port->number);
 
 	if (edge_port == NULL)
 		return;
@@ -2367,7 +2364,7 @@ static int get_serial_info(struct edgepo
 
 	tmp.type		= PORT_16550A;
 	tmp.line		= edge_port->port->serial->minor;
-	tmp.port		= edge_port->port->number;
+	tmp.port		= edge_port->port->port_number;
 	tmp.irq			= 0;
 	tmp.flags		= ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 	tmp.xmit_fifo_size	= edge_port->port->bulk_out_size;
@@ -2386,7 +2383,7 @@ static int edge_ioctl(struct tty_struct
 	struct usb_serial_port *port = tty->driver_data;
 	struct edgeport_port *edge_port = usb_get_serial_port_data(port);
 
-	dev_dbg(&port->dev, "%s - port %d, cmd = 0x%x\n", __func__, port->number, cmd);
+	dev_dbg(&port->dev, "%s - cmd = 0x%x\n", __func__, cmd);
 
 	switch (cmd) {
 	case TIOCGSERIAL:
--- a/drivers/usb/serial/keyspan.c
+++ b/drivers/usb/serial/keyspan.c
@@ -152,7 +152,7 @@ static void keyspan_set_termios(struct t
 	p_priv = usb_get_serial_port_data(port);
 	d_details = p_priv->device_details;
 	cflag = tty->termios.c_cflag;
-	device_port = port->number - port->serial->minor;
+	device_port = port->port_number;
 
 	/* Baud rate calculation takes baud rate as an integer
 	   so other rates can be generated if desired. */
@@ -234,8 +234,8 @@ static int keyspan_write(struct tty_stru
 		dataOffset = 1;
 	}
 
-	dev_dbg(&port->dev, "%s - for port %d (%d chars), flip=%d\n",
-		__func__, port->number, count, p_priv->out_flip);
+	dev_dbg(&port->dev, "%s - %d chars, flip=%d\n", __func__, count,
+		p_priv->out_flip);
 
 	for (left = count; left > 0; left -= todo) {
 		todo = left;
@@ -1050,7 +1050,7 @@ static int keyspan_open(struct tty_struc
 	/* get the terminal config for the setup message now so we don't
 	 * need to send 2 of them */
 
-	device_port = port->number - port->serial->minor;
+	device_port = port->port_number;
 	if (tty) {
 		cflag = tty->termios.c_cflag;
 		/* Baud rate calculation takes baud rate as an integer
@@ -1556,7 +1556,7 @@ static int keyspan_usa26_send_setup(stru
 	s_priv = usb_get_serial_data(serial);
 	p_priv = usb_get_serial_port_data(port);
 	d_details = s_priv->device_details;
-	device_port = port->number - port->serial->minor;
+	device_port = port->port_number;
 
 	this_urb = p_priv->outcont_urb;
 
@@ -1700,7 +1700,7 @@ static int keyspan_usa28_send_setup(stru
 	s_priv = usb_get_serial_data(serial);
 	p_priv = usb_get_serial_port_data(port);
 	d_details = s_priv->device_details;
-	device_port = port->number - port->serial->minor;
+	device_port = port->port_number;
 
 	/* only do something if we have a bulk out endpoint */
 	this_urb = p_priv->outcont_urb;
@@ -1830,17 +1830,16 @@ static int keyspan_usa49_send_setup(stru
 	this_urb = s_priv->glocont_urb;
 
 	/* Work out which port within the device is being setup */
-	device_port = port->number - port->serial->minor;
+	device_port = port->port_number;
 
 	/* Make sure we have an urb then send the message */
 	if (this_urb == NULL) {
-		dev_dbg(&port->dev, "%s - oops no urb for port %d.\n", __func__, port->number);
+		dev_dbg(&port->dev, "%s - oops no urb for port.\n", __func__);
 		return -1;
 	}
 
-	dev_dbg(&port->dev, "%s - endpoint %d port %d (%d)\n",
-		__func__, usb_pipeendpoint(this_urb->pipe),
-		port->number, device_port);
+	dev_dbg(&port->dev, "%s - endpoint %d (%d)\n",
+		__func__, usb_pipeendpoint(this_urb->pipe), device_port);
 
 	/* Save reset port val for resend.
 	   Don't overwrite resend for open/close condition. */
@@ -1855,7 +1854,6 @@ static int keyspan_usa49_send_setup(stru
 
 	memset(&msg, 0, sizeof(struct keyspan_usa49_portControlMessage));
 
-	/*msg.portNumber = port->number;*/
 	msg.portNumber = device_port;
 
 	/* Only set baud rate if it's changed */
@@ -2145,12 +2143,11 @@ static int keyspan_usa67_send_setup(stru
 	this_urb = s_priv->glocont_urb;
 
 	/* Work out which port within the device is being setup */
-	device_port = port->number - port->serial->minor;
+	device_port = port->port_number;
 
 	/* Make sure we have an urb then send the message */
 	if (this_urb == NULL) {
-		dev_dbg(&port->dev, "%s - oops no urb for port %d.\n", __func__,
-			port->number);
+		dev_dbg(&port->dev, "%s - oops no urb for port.\n", __func__);
 		return -1;
 	}
 
@@ -2391,7 +2388,7 @@ static int keyspan_port_probe(struct usb
 	/* Setup values for the various callback routines */
 	cback = &keyspan_callbacks[d_details->msg_format];
 
-	port_num = port->number - port->serial->minor;
+	port_num = port->port_number;
 
 	/* Do indat endpoints first, once for each flip */
 	endp = d_details->indat_endpoints[port_num];
--- a/drivers/usb/serial/metro-usb.c
+++ b/drivers/usb/serial/metro-usb.c
@@ -224,8 +224,8 @@ static int metrousb_open(struct tty_stru
 	result = metrousb_send_unidirectional_cmd(UNI_CMD_OPEN, port);
 	if (result) {
 		dev_err(&port->dev,
-			"%s - failed to configure device for port number=%d, error code=%d\n",
-			__func__, port->number, result);
+			"%s - failed to configure device, error code=%d\n",
+			__func__, result);
 		goto exit;
 	}
 
--- a/drivers/usb/serial/mos7720.c
+++ b/drivers/usb/serial/mos7720.c
@@ -1047,7 +1047,7 @@ static int mos7720_open(struct tty_struc
 	  *
 	  * 0x08 : SP1/2 Control Reg
 	  */
-	port_number = port->number - port->serial->minor;
+	port_number = port->port_number;
 	read_mos_reg(serial, port_number, LSR, &data);
 
 	dev_dbg(&port->dev, "SS::%p LSR:%x\n", mos7720_port, data);
@@ -1066,7 +1066,7 @@ static int mos7720_open(struct tty_struc
 
 	write_mos_reg(serial, port_number, SP_CONTROL_REG, 0x00);
 	read_mos_reg(serial, dummy, SP_CONTROL_REG, &data);
-	data = data | (port->number - port->serial->minor + 1);
+	data = data | (port->port_number + 1);
 	write_mos_reg(serial, dummy, SP_CONTROL_REG, data);
 	mos7720_port->shadowLCR = 0x83;
 	write_mos_reg(serial, port_number, LCR, mos7720_port->shadowLCR);
@@ -1147,8 +1147,8 @@ static void mos7720_close(struct usb_ser
 	usb_kill_urb(port->write_urb);
 	usb_kill_urb(port->read_urb);
 
-	write_mos_reg(serial, port->number - port->serial->minor, MCR, 0x00);
-	write_mos_reg(serial, port->number - port->serial->minor, IER, 0x00);
+	write_mos_reg(serial, port->port_number, MCR, 0x00);
+	write_mos_reg(serial, port->port_number, IER, 0x00);
 
 	mos7720_port->open = 0;
 }
@@ -1172,8 +1172,7 @@ static void mos7720_break(struct tty_str
 		data = mos7720_port->shadowLCR & ~UART_LCR_SBC;
 
 	mos7720_port->shadowLCR  = data;
-	write_mos_reg(serial, port->number - port->serial->minor,
-		      LCR, mos7720_port->shadowLCR);
+	write_mos_reg(serial, port->port_number, LCR, mos7720_port->shadowLCR);
 }
 
 /*
@@ -1304,8 +1303,8 @@ static void mos7720_throttle(struct tty_
 	/* if we are implementing RTS/CTS, toggle that line */
 	if (tty->termios.c_cflag & CRTSCTS) {
 		mos7720_port->shadowMCR &= ~UART_MCR_RTS;
-		write_mos_reg(port->serial, port->number - port->serial->minor,
-			      MCR, mos7720_port->shadowMCR);
+		write_mos_reg(port->serial, port->port_number, MCR,
+			      mos7720_port->shadowMCR);
 		if (status != 0)
 			return;
 	}
@@ -1336,8 +1335,8 @@ static void mos7720_unthrottle(struct tt
 	/* if we are implementing RTS/CTS, toggle that line */
 	if (tty->termios.c_cflag & CRTSCTS) {
 		mos7720_port->shadowMCR |= UART_MCR_RTS;
-		write_mos_reg(port->serial, port->number - port->serial->minor,
-			      MCR, mos7720_port->shadowMCR);
+		write_mos_reg(port->serial, port->port_number, MCR,
+			      mos7720_port->shadowMCR);
 		if (status != 0)
 			return;
 	}
@@ -1361,7 +1360,7 @@ static int set_higher_rates(struct mosch
 	 *      Init Sequence for higher rates
 	 ***********************************************/
 	dev_dbg(&port->dev, "Sending Setting Commands ..........\n");
-	port_number = port->number - port->serial->minor;
+	port_number = port->port_number;
 
 	write_mos_reg(serial, port_number, IER, 0x00);
 	write_mos_reg(serial, port_number, FCR, 0x00);
@@ -1487,7 +1486,7 @@ static int send_cmd_write_baud_rate(stru
 	port = mos7720_port->port;
 	serial = port->serial;
 
-	number = port->number - port->serial->minor;
+	number = port->port_number;
 	dev_dbg(&port->dev, "%s - baud = %d\n", __func__, baudrate);
 
 	/* Calculate the Divisor */
@@ -1538,7 +1537,7 @@ static void change_port_settings(struct
 
 	port = mos7720_port->port;
 	serial = port->serial;
-	port_number = port->number - port->serial->minor;
+	port_number = port->port_number;
 
 	if (!mos7720_port->open) {
 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
@@ -1731,7 +1730,7 @@ static int get_lsr_info(struct tty_struc
 	struct usb_serial_port *port = tty->driver_data;
 	unsigned int result = 0;
 	unsigned char data = 0;
-	int port_number = port->number - port->serial->minor;
+	int port_number = port->port_number;
 	int count;
 
 	count = mos7720_chars_in_buffer(tty);
@@ -1793,8 +1792,8 @@ static int mos7720_tiocmset(struct tty_s
 		mcr &= ~UART_MCR_LOOP;
 
 	mos7720_port->shadowMCR = mcr;
-	write_mos_reg(port->serial, port->number - port->serial->minor,
-		      MCR, mos7720_port->shadowMCR);
+	write_mos_reg(port->serial, port->port_number, MCR,
+		      mos7720_port->shadowMCR);
 
 	return 0;
 }
@@ -1838,8 +1837,8 @@ static int set_modem_info(struct moschip
 	}
 
 	mos7720_port->shadowMCR = mcr;
-	write_mos_reg(port->serial, port->number - port->serial->minor,
-		      MCR, mos7720_port->shadowMCR);
+	write_mos_reg(port->serial, port->port_number, MCR,
+		      mos7720_port->shadowMCR);
 
 	return 0;
 }
@@ -1856,7 +1855,7 @@ static int get_serial_info(struct moschi
 
 	tmp.type		= PORT_16550A;
 	tmp.line		= mos7720_port->port->serial->minor;
-	tmp.port		= mos7720_port->port->number;
+	tmp.port		= mos7720_port->port->port_number;
 	tmp.irq			= 0;
 	tmp.flags		= ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 	tmp.xmit_fifo_size	= NUM_URBS * URB_TRANSFER_BUFFER_SIZE;
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -303,15 +303,12 @@ static int mos7840_set_uart_reg(struct u
 	/* For the UART control registers, the application number need
 	   to be Or'ed */
 	if (port->serial->num_ports == 4) {
-		val |= (((__u16) port->number -
-				(__u16) (port->serial->minor)) + 1) << 8;
+		val |= ((__u16)port->port_number + 1) << 8;
 	} else {
-		if (((__u16) port->number - (__u16) (port->serial->minor)) == 0) {
-			val |= (((__u16) port->number -
-			      (__u16) (port->serial->minor)) + 1) << 8;
+		if (port->port_number == 0) {
+			val |= ((__u16)port->port_number + 1) << 8;
 		} else {
-			val |= (((__u16) port->number -
-			      (__u16) (port->serial->minor)) + 2) << 8;
+			val |= ((__u16)port->port_number + 2) << 8;
 		}
 	}
 	dev_dbg(&port->dev, "%s application number is %x\n", __func__, val);
@@ -340,16 +337,12 @@ static int mos7840_get_uart_reg(struct u
 
 	/* Wval  is same as application number */
 	if (port->serial->num_ports == 4) {
-		Wval =
-		    (((__u16) port->number - (__u16) (port->serial->minor)) +
-		     1) << 8;
+		Wval = ((__u16)port->port_number + 1) << 8;
 	} else {
-		if (((__u16) port->number - (__u16) (port->serial->minor)) == 0) {
-			Wval = (((__u16) port->number -
-			      (__u16) (port->serial->minor)) + 1) << 8;
+		if (port->port_number == 0) {
+			Wval = ((__u16)port->port_number + 1) << 8;
 		} else {
-			Wval = (((__u16) port->number -
-			      (__u16) (port->serial->minor)) + 2) << 8;
+			Wval = ((__u16)port->port_number + 2) << 8;
 		}
 	}
 	dev_dbg(&port->dev, "%s application number is %x\n", __func__, Wval);
@@ -631,9 +624,7 @@ static void mos7840_interrupt_callback(s
 
 	for (i = 0; i < serial->num_ports; i++) {
 		mos7840_port = mos7840_get_port_private(serial->port[i]);
-		wval =
-		    (((__u16) serial->port[i]->number -
-		      (__u16) (serial->minor)) + 1) << 8;
+		wval = ((__u16)serial->port[i]->port_number + 1) << 8;
 		if (mos7840_port->open) {
 			if (sp[i] & 0x01) {
 				dev_dbg(&urb->dev->dev, "SP%d No Interrupt !!!\n", i);
@@ -1065,8 +1056,8 @@ static int mos7840_open(struct tty_struc
 	 * (can't set it up in mos7840_startup as the  *
 	 * structures were not set up at that time.)   */
 
-	dev_dbg(&port->dev, "port number is %d\n", port->number);
-	dev_dbg(&port->dev, "serial number is %d\n", port->serial->minor);
+	dev_dbg(&port->dev, "port number is %d\n", port->port_number);
+	dev_dbg(&port->dev, "minor number is %d\n", port->serial->minor);
 	dev_dbg(&port->dev, "Bulkin endpoint is %d\n", port->bulk_in_endpointAddress);
 	dev_dbg(&port->dev, "BulkOut endpoint is %d\n", port->bulk_out_endpointAddress);
 	dev_dbg(&port->dev, "Interrupt endpoint is %d\n", port->interrupt_in_endpointAddress);
@@ -1074,9 +1065,7 @@ static int mos7840_open(struct tty_struc
 	mos7840_port->read_urb = port->read_urb;
 
 	/* set up our bulk in urb */
-	if ((serial->num_ports == 2)
-		&& ((((__u16)port->number -
-			(__u16)(port->serial->minor)) % 2) != 0)) {
+	if ((serial->num_ports == 2) && (((__u16)port->port_number % 2) != 0)) {
 		usb_fill_bulk_urb(mos7840_port->read_urb,
 			serial->dev,
 			usb_rcvbulkpipe(serial->dev,
@@ -1199,7 +1188,7 @@ static void mos7840_close(struct usb_ser
 	mos7840_port->read_urb_busy = false;
 
 	port0->open_ports--;
-	dev_dbg(&port->dev, "%s in close%d:in port%d\n", __func__, port0->open_ports, port->number);
+	dev_dbg(&port->dev, "%s in close%d\n", __func__, port0->open_ports);
 	if (port0->open_ports == 0) {
 		if (serial->port[0]->interrupt_in_urb) {
 			dev_dbg(&port->dev, "Shutdown interrupt_in_urb\n");
@@ -1435,9 +1424,7 @@ static int mos7840_write(struct tty_stru
 	memcpy(urb->transfer_buffer, current_position, transfer_size);
 
 	/* fill urb with data and submit  */
-	if ((serial->num_ports == 2)
-		&& ((((__u16)port->number -
-			(__u16)(port->serial->minor)) % 2) != 0)) {
+	if ((serial->num_ports == 2) && (((__u16)port->port_number % 2) != 0)) {
 		usb_fill_bulk_urb(urb,
 			serial->dev,
 			usb_sndbulkpipe(serial->dev,
@@ -1732,10 +1719,9 @@ static int mos7840_send_cmd_write_baud_r
 	if (mos7840_serial_paranoia_check(port->serial, __func__))
 		return -1;
 
-	number = mos7840_port->port->number - mos7840_port->port->serial->minor;
+	number = mos7840_port->port->port_number;
 
-	dev_dbg(&port->dev, "%s - port = %d, baud = %d\n", __func__,
-		mos7840_port->port->number, baudRate);
+	dev_dbg(&port->dev, "%s - baud = %d\n", __func__, baudRate);
 	/* reset clk_uart_sel in spregOffset */
 	if (baudRate > 115200) {
 #ifdef HW_flow_control
@@ -2016,7 +2002,6 @@ static void mos7840_set_termios(struct t
 		tty->termios.c_cflag, RELEVANT_IFLAG(tty->termios.c_iflag));
 	dev_dbg(&port->dev, "%s - old clfag %08x old iflag %08x\n", __func__,
 		old_termios->c_cflag, RELEVANT_IFLAG(old_termios->c_iflag));
-	dev_dbg(&port->dev, "%s - port %d\n", __func__, port->number);
 
 	/* change the port settings to the new ones specified */
 
@@ -2084,7 +2069,7 @@ static int mos7840_get_serial_info(struc
 
 	tmp.type = PORT_16550A;
 	tmp.line = mos7840_port->port->serial->minor;
-	tmp.port = mos7840_port->port->number;
+	tmp.port = mos7840_port->port->port_number;
 	tmp.irq = 0;
 	tmp.flags = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 	tmp.xmit_fifo_size = NUM_URBS * URB_TRANSFER_BUFFER_SIZE;
@@ -2240,7 +2225,7 @@ static int mos7840_port_probe(struct usb
 	/* we set up the pointers to the endpoints in the mos7840_open *
 	 * function, as the structures aren't created yet.             */
 
-	pnum = port->number - serial->minor;
+	pnum = port->port_number;
 
 	dev_dbg(&port->dev, "mos7840_startup: configuring port %d\n", pnum);
 	mos7840_port = kzalloc(sizeof(struct moschip_port), GFP_KERNEL);
@@ -2261,7 +2246,6 @@ static int mos7840_port_probe(struct usb
 	 * usb-serial.c:get_free_serial() and cannot therefore be used
 	 * to index device instances */
 	mos7840_port->port_num = pnum + 1;
-	dev_dbg(&port->dev, "port->number = %d\n", port->number);
 	dev_dbg(&port->dev, "port->serial->minor = %d\n", port->serial->minor);
 	dev_dbg(&port->dev, "mos7840_port->port_num = %d\n", mos7840_port->port_num);
 	dev_dbg(&port->dev, "serial->minor = %d\n", serial->minor);
--- a/drivers/usb/serial/opticon.c
+++ b/drivers/usb/serial/opticon.c
@@ -367,7 +367,7 @@ static int opticon_ioctl(struct tty_stru
 {
 	struct usb_serial_port *port = tty->driver_data;
 
-	dev_dbg(&port->dev, "%s - port %d, cmd = 0x%x\n", __func__, port->number, cmd);
+	dev_dbg(&port->dev, "%s - cmd = 0x%x\n", __func__, cmd);
 
 	switch (cmd) {
 	case TIOCGSERIAL:
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -642,7 +642,7 @@ static int pl2303_ioctl(struct tty_struc
 		memset(&ser, 0, sizeof ser);
 		ser.type = PORT_16654;
 		ser.line = port->serial->minor;
-		ser.port = port->number;
+		ser.port = port->port_number;
 		ser.baud_base = 460800;
 
 		if (copy_to_user((void __user *)arg, &ser, sizeof ser))
--- a/drivers/usb/serial/quatech2.c
+++ b/drivers/usb/serial/quatech2.c
@@ -343,7 +343,7 @@ static int qt2_open(struct tty_struct *t
 	int status;
 	unsigned long flags;
 
-	device_port = (u16) (port->number - port->serial->minor);
+	device_port = port->port_number;
 
 	serial = port->serial;
 
@@ -388,9 +388,8 @@ static int qt2_open(struct tty_struct *t
 	status = qt2_set_port_config(serial->dev, device_port,
 				     DEFAULT_BAUD_RATE, UART_LCR_WLEN8);
 	if (status < 0) {
-		dev_err(&port->dev,
-			"%s - initial setup failed for port %i (%i)\n",
-			__func__, port->number, device_port);
+		dev_err(&port->dev, "%s - initial setup failed (%i)\n",
+			__func__, device_port);
 		return status;
 	}
 
--- a/drivers/usb/serial/sierra.c
+++ b/drivers/usb/serial/sierra.c
@@ -914,7 +914,7 @@ static int sierra_port_probe(struct usb_
 		/* This is really the usb-serial port number of the interface
 		 * rather than the interface number.
 		 */
-		ifnum = port->number - serial->minor;
+		ifnum = port->port_number;
 		himemoryp = &typeA_interface_list;
 	}
 
--- a/drivers/usb/serial/ti_usb_3410_5052.c
+++ b/drivers/usb/serial/ti_usb_3410_5052.c
@@ -476,7 +476,7 @@ static int ti_open(struct tty_struct *tt
 	if (mutex_lock_interruptible(&tdev->td_open_close_lock))
 		return -ERESTARTSYS;
 
-	port_number = port->number - port->serial->minor;
+	port_number = port->port_number;
 
 	tport->tp_msr = 0;
 	tport->tp_shadow_mcr |= (TI_MCR_RTS | TI_MCR_DTR);
@@ -618,7 +618,7 @@ static void ti_close(struct usb_serial_p
 	kfifo_reset_out(&tport->write_fifo);
 	spin_unlock_irqrestore(&tport->tp_lock, flags);
 
-	port_number = port->number - port->serial->minor;
+	port_number = port->port_number;
 
 	dev_dbg(&port->dev, "%s - sending TI_CLOSE_PORT\n", __func__);
 	status = ti_command_out_sync(tdev, TI_CLOSE_PORT,
@@ -776,7 +776,7 @@ static void ti_set_termios(struct tty_st
 	tcflag_t cflag, iflag;
 	int baud;
 	int status;
-	int port_number = port->number - port->serial->minor;
+	int port_number = port->port_number;
 	unsigned int mcr;
 
 	cflag = tty->termios.c_cflag;
@@ -1262,7 +1262,7 @@ static int ti_get_lsr(struct ti_port *tp
 	int size, status;
 	struct ti_device *tdev = tport->tp_tdev;
 	struct usb_serial_port *port = tport->tp_port;
-	int port_number = port->number - port->serial->minor;
+	int port_number = port->port_number;
 	struct ti_port_status *data;
 
 	size = sizeof(struct ti_port_status);
@@ -1309,7 +1309,7 @@ static int ti_get_serial_info(struct ti_
 
 	ret_serial.type = PORT_16550A;
 	ret_serial.line = port->serial->minor;
-	ret_serial.port = port->number - port->serial->minor;
+	ret_serial.port = port->port_number;
 	ret_serial.flags = tport->tp_flags;
 	ret_serial.xmit_fifo_size = TI_WRITE_BUF_SIZE;
 	ret_serial.baud_base = tport->tp_tdev->td_is_3410 ? 921600 : 460800;
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -105,9 +105,10 @@ static struct usb_serial *get_free_seria
 		*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) {
+		for (i = *minor; (i < (*minor + num_ports)) && (i < SERIAL_TTY_MINORS); ++i, ++j) {
 			serial_table[i] = serial;
-			serial->port[j++]->number = i;
+			serial->port[j]->minor = i;
+			serial->port[j]->port_number = i - *minor;
 		}
 		mutex_unlock(&table_lock);
 		return serial;
@@ -1048,7 +1049,7 @@ static int usb_serial_probe(struct usb_i
 	/* register all of the individual ports with the driver core */
 	for (i = 0; i < num_ports; ++i) {
 		port = serial->port[i];
-		dev_set_name(&port->dev, "ttyUSB%d", port->number);
+		dev_set_name(&port->dev, "ttyUSB%d", port->minor);
 		dev_dbg(ddev, "registering %s", dev_name(&port->dev));
 		device_enable_async_suspend(&port->dev);
 
--- a/drivers/usb/serial/usb_wwan.c
+++ b/drivers/usb/serial/usb_wwan.c
@@ -125,7 +125,7 @@ static int get_serial_info(struct usb_se
 
 	memset(&tmp, 0, sizeof(tmp));
 	tmp.line            = port->serial->minor;
-	tmp.port            = port->number;
+	tmp.port            = port->port_number;
 	tmp.baud_base       = tty_get_baud_rate(port->port.tty);
 	tmp.close_delay	    = port->port.close_delay / 10;
 	tmp.closing_wait    = port->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
--- a/drivers/usb/serial/whiteheat.c
+++ b/drivers/usb/serial/whiteheat.c
@@ -462,7 +462,7 @@ static int whiteheat_ioctl(struct tty_st
 		memset(&serstruct, 0, sizeof(serstruct));
 		serstruct.type = PORT_16654;
 		serstruct.line = port->serial->minor;
-		serstruct.port = port->number;
+		serstruct.port = port->port_number;
 		serstruct.flags = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 		serstruct.xmit_fifo_size = kfifo_size(&port->write_fifo);
 		serstruct.custom_divisor = 0;
@@ -626,7 +626,7 @@ static int firm_open(struct usb_serial_p
 {
 	struct whiteheat_simple open_command;
 
-	open_command.port = port->number - port->serial->minor + 1;
+	open_command.port = port->port_number + 1;
 	return firm_send_command(port, WHITEHEAT_OPEN,
 		(__u8 *)&open_command, sizeof(open_command));
 }
@@ -636,7 +636,7 @@ static int firm_close(struct usb_serial_
 {
 	struct whiteheat_simple close_command;
 
-	close_command.port = port->number - port->serial->minor + 1;
+	close_command.port = port->port_number + 1;
 	return firm_send_command(port, WHITEHEAT_CLOSE,
 			(__u8 *)&close_command, sizeof(close_command));
 }
@@ -649,7 +649,7 @@ static void firm_setup_port(struct tty_s
 	struct whiteheat_port_settings port_settings;
 	unsigned int cflag = tty->termios.c_cflag;
 
-	port_settings.port = port->number + 1;
+	port_settings.port = port->port_number + 1;
 
 	/* get the byte size */
 	switch (cflag & CSIZE) {
@@ -726,7 +726,7 @@ static int firm_set_rts(struct usb_seria
 {
 	struct whiteheat_set_rdb rts_command;
 
-	rts_command.port = port->number - port->serial->minor + 1;
+	rts_command.port = port->port_number + 1;
 	rts_command.state = onoff;
 	return firm_send_command(port, WHITEHEAT_SET_RTS,
 			(__u8 *)&rts_command, sizeof(rts_command));
@@ -737,7 +737,7 @@ static int firm_set_dtr(struct usb_seria
 {
 	struct whiteheat_set_rdb dtr_command;
 
-	dtr_command.port = port->number - port->serial->minor + 1;
+	dtr_command.port = port->port_number + 1;
 	dtr_command.state = onoff;
 	return firm_send_command(port, WHITEHEAT_SET_DTR,
 			(__u8 *)&dtr_command, sizeof(dtr_command));
@@ -748,7 +748,7 @@ static int firm_set_break(struct usb_ser
 {
 	struct whiteheat_set_rdb break_command;
 
-	break_command.port = port->number - port->serial->minor + 1;
+	break_command.port = port->port_number + 1;
 	break_command.state = onoff;
 	return firm_send_command(port, WHITEHEAT_SET_BREAK,
 			(__u8 *)&break_command, sizeof(break_command));
@@ -759,7 +759,7 @@ static int firm_purge(struct usb_serial_
 {
 	struct whiteheat_purge purge_command;
 
-	purge_command.port = port->number - port->serial->minor + 1;
+	purge_command.port = port->port_number + 1;
 	purge_command.what = rxtx;
 	return firm_send_command(port, WHITEHEAT_PURGE,
 			(__u8 *)&purge_command, sizeof(purge_command));
@@ -770,7 +770,7 @@ static int firm_get_dtr_rts(struct usb_s
 {
 	struct whiteheat_simple get_dr_command;
 
-	get_dr_command.port = port->number - port->serial->minor + 1;
+	get_dr_command.port = port->port_number + 1;
 	return firm_send_command(port, WHITEHEAT_GET_DTR_RTS,
 			(__u8 *)&get_dr_command, sizeof(get_dr_command));
 }
@@ -780,7 +780,7 @@ static int firm_report_tx_done(struct us
 {
 	struct whiteheat_simple close_command;
 
-	close_command.port = port->number - port->serial->minor + 1;
+	close_command.port = port->port_number + 1;
 	return firm_send_command(port, WHITEHEAT_REPORT_TX_DONE,
 			(__u8 *)&close_command, sizeof(close_command));
 }
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -37,7 +37,8 @@
  * @serial: pointer back to the struct usb_serial owner of this port.
  * @port: pointer to the corresponding tty_port for this port.
  * @lock: spinlock to grab when updating portions of this structure.
- * @number: the number of the port (the minor number).
+ * @minor: the minor number of the port
+ * @port_number: the port number of this struct usb_serial_device (starts at 0)
  * @interrupt_in_buffer: pointer to the interrupt in buffer for this port.
  * @interrupt_in_urb: pointer to the interrupt in struct urb for this port.
  * @interrupt_in_endpointAddress: endpoint address for the interrupt in pipe
@@ -80,7 +81,8 @@ struct usb_serial_port {
 	struct usb_serial	*serial;
 	struct tty_port		port;
 	spinlock_t		lock;
-	unsigned char		number;
+	u32			minor;
+	u8			port_number;
 
 	unsigned char		*interrupt_in_buffer;
 	struct urb		*interrupt_in_urb;

Re: [PATCH 1/3] USB: serial: ports: add minor and port number

[Johan Hovold]

On Wed, Jun 05, 2013 at 10:55:39AM -0700, Greg KH wrote:
> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> The usb_serial_port structure had the number field, which was the minor
> number for the port, which almost no one really cared about.  They
> really wanted the number of the port within the device, which you had to
> subtract from the minor of the parent usb_serial_device structure.  To
> clean this up, provide the real minor number of the port, and the number
> of the port within the serial device separately, as these numbers might
> not be related in the future.
> 
> Bonus is that this cleans up a lot of logic in the drivers, and saves
> lines overall.
> 
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

> --- a/drivers/usb/serial/io_edgeport.c
> +++ b/drivers/usb/serial/io_edgeport.c

> @@ -2302,7 +2293,7 @@ static int send_cmd_write_baud_rate(stru
>  
>  	/* Restore original value to disable access to divisor latch */
>  	MAKE_CMD_WRITE_REG(&currCmd, &cmdLen, number, LCR,
> -						edge_port->shadowLCR);
> +			   edge_port->shadowLCR);

Unintended indentation change?

>  	status = write_cmd_usb(edge_port, cmdBuffer, cmdLen);
>  	if (status) {

> --- a/drivers/usb/serial/whiteheat.c
> +++ b/drivers/usb/serial/whiteheat.c

> @@ -649,7 +649,7 @@ static void firm_setup_port(struct tty_s
>  	struct whiteheat_port_settings port_settings;
>  	unsigned int cflag = tty->termios.c_cflag;
>  
> -	port_settings.port = port->number + 1;
> +	port_settings.port = port->port_number + 1;

This is a bug that should be fixed separately and backported, as it
prevents port configuration (e.g. set_termios) for ports with minor
number greater than 0.

I took the liberty to prepare a separate patch for v3.10, which you
could rebase the series on.

>  	/* get the byte size */
>  	switch (cflag & CSIZE) {

> --- a/include/linux/usb/serial.h
> +++ b/include/linux/usb/serial.h
> @@ -37,7 +37,8 @@
>   * @serial: pointer back to the struct usb_serial owner of this port.
>   * @port: pointer to the corresponding tty_port for this port.
>   * @lock: spinlock to grab when updating portions of this structure.
> - * @number: the number of the port (the minor number).
> + * @minor: the minor number of the port
> + * @port_number: the port number of this struct usb_serial_device (starts at 0)

Maybe 

	@port_number: the struct usb_serial port number of this port (starts at 0)

or something similar, would be more clear?

>   * @interrupt_in_buffer: pointer to the interrupt in buffer for this port.
>   * @interrupt_in_urb: pointer to the interrupt in struct urb for this port.
>   * @interrupt_in_endpointAddress: endpoint address for the interrupt in pipe

Looks good otherwise.

Thanks,
Johan

[PATCH] USB: whiteheat: fix broken port configuration

[Johan Hovold]

When configuring the port (e.g. set_termios) the port minor number
rather than the port number was used in the request (and they only
coincide for minor number 0).

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <jhovold@gmail.com>
---
 drivers/usb/serial/whiteheat.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/serial/whiteheat.c b/drivers/usb/serial/whiteheat.c
index b9fca35..347caad 100644
--- a/drivers/usb/serial/whiteheat.c
+++ b/drivers/usb/serial/whiteheat.c
@@ -649,7 +649,7 @@ static void firm_setup_port(struct tty_struct *tty)
 	struct whiteheat_port_settings port_settings;
 	unsigned int cflag = tty->termios.c_cflag;
 
-	port_settings.port = port->number + 1;
+	port_settings.port = port->number - port->serial->minor + 1;
 
 	/* get the byte size */
 	switch (cflag & CSIZE) {
-- 
1.8.2.1

Re: [PATCH 0/3] Increase the number of USB to serial devices we can support at once

[Tobias Winter]

Hi Greg,

On 06/05/2013 07:54 PM, Greg KH wrote:
> Here are 3 patches that I've tested out on my system with only a small
> number of devices, but it seems to work, so why not let others try it
> out...

It compiles and runs without any errors. My current setup has 272 ftdi
devices connected:

rescue on 172.18.24.141:/dev$ uname -a
Linux bigrescue 3.10.0-rc3+ #1 SMP Thu Jun 6 12:21:06 CEST 2013 x86_64
GNU/Linux
rescue on 172.18.24.141:/dev$ dmesg | tail -n 15
[ 3361.898725] usb 3-1.4.4: usb_probe_device
[ 3361.898750] usb 3-1.4.4: configuration #1 chosen from 1 choice
[ 3361.901598] usb 3-1.4.4: adding 3-1.4.4:1.0 (config #1, interface 0)
[ 3361.906802] ftdi_sio 3-1.4.4:1.0: usb_probe_interface
[ 3361.906830] ftdi_sio 3-1.4.4:1.0: usb_probe_interface - got id
[ 3361.906875] ftdi_sio 3-1.4.4:1.0: FTDI USB Serial Device converter
detected
[ 3361.932490] usb 3-1.4.4: Detected FT232RL
[ 3361.952189] usb 3-1.4.4: Number of endpoints 2
[ 3361.972791] usb 3-1.4.4: Endpoint 1 MaxPacketSize 64
[ 3361.994656] usb 3-1.4.4: Endpoint 2 MaxPacketSize 64
[ 3362.016309] usb 3-1.4.4: Setting MaxPacketSize 64
[ 3362.039764] usb 3-1.4.4: FTDI USB Serial Device converter now
attached to ttyUSB271
[ 3362.075248] hub 3-1.2:1.0: state 7 ports 4 chg 0000 evt 0010
[ 3362.075676] hub 3-1.3:1.0: state 7 ports 4 chg 0000 evt 0010
[ 3362.076659] hub 3-1.4:1.0: state 7 ports 4 chg 0000 evt 0010

Sadly I only have FTDI single port interfaces and am therefore unable to
test with other devices.

Thanks for the effort!

Tobias

Re: [PATCH 2/3] USB: serial: make minor allocation dynamic

[Johan Hovold]

On Wed, Jun 05, 2013 at 10:54:55AM -0700, Greg KH wrote:
> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> 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>

[...]

> -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;

You could use SERIAL_TTY_NO_MINOR here -- if needed at all, as it has
already been set in create_serial.

> +	for (i = 0; i < num_ports; ++i) {
> +		x = get_free_port(serial->port[i]);
> +		if (x < 0)
> +			goto error;
> +		if (*minor == 0xffffffff)
> +			*minor = x;

We must not update *minor until all port minors have been allocated, or
idr_remove might get called for unallocated minors or even minor numbers
of other ports in return_serial when the serial struct is destroyed.

> +		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]->minor);
> +	return x;

table_lock?

>  }
>  
>  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]->minor);
>  	mutex_unlock(&table_lock);
>  }
>  

[...]

Looks good otherwise.

Thanks,
Johan

Re: [PATCH 0/3] Increase the number of USB to serial devices we can support at once

[Dave Jones]

On Wed, Jun 05, 2013 at 10:54:26AM -0700, Greg KH wrote:
 > Here are 3 patches that I've tested out on my system with only a small
 > number of devices, but it seems to work, so why not let others try it
 > out...
 > 
 > These patches make the USB to serial core have the ability to support up
 > to 3000 devices at once now.  

I'm curious how this works. What systems have 3000 usb ports ?
Or are there some kind of multiplexer devices out there ?
(If so, I'd like a link, I could use one of those).

	Dave

Re: [PATCH 0/3] Increase the number of USB to serial devices we can support at once

[Greg KH]

On Thu, Jun 06, 2013 at 11:01:12AM -0400, Dave Jones wrote:
> On Wed, Jun 05, 2013 at 10:54:26AM -0700, Greg KH wrote:
>  > Here are 3 patches that I've tested out on my system with only a small
>  > number of devices, but it seems to work, so why not let others try it
>  > out...
>  > 
>  > These patches make the USB to serial core have the ability to support up
>  > to 3000 devices at once now.  
> 
> I'm curious how this works. What systems have 3000 usb ports ?
> Or are there some kind of multiplexer devices out there ?
> (If so, I'd like a link, I could use one of those).

You don't need a multiplexer, you can have a bunch of different USB root
hubs in PCI slots, with USB hubs plugged into them, and lots of
multi-port USB devices connected to them.  Tobias has such a system with
272 single-port USB to serial devices connected, so it's not impossible
to create.

In thinking about it some more, I'll change that number to 500 for now,
as it's a static array within the tty layer, and then work on making
that dynamic so we don't have any limitations other than the number of
minor numbers for a single major.

thanks,

greg k-h

Re: [PATCH 0/3] Increase the number of USB to serial devices we can support at once

[Tobias Winter]

On 06.06.2013 17:21, Greg KH wrote:
> On Thu, Jun 06, 2013 at 11:01:12AM -0400, Dave Jones wrote:
>> On Wed, Jun 05, 2013 at 10:54:26AM -0700, Greg KH wrote:
>>  > These patches make the USB to serial core have the ability to support up
>>  > to 3000 devices at once now.  
>>
>> I'm curious how this works. What systems have 3000 usb ports ?
Surely no one thought that a system could have 255 devices of that sort
~15 years ago. Isn't the idea always to support more that what is possible?
>> Or are there some kind of multiplexer devices out there ?
>> (If so, I'd like a link, I could use one of those).
> 
> You don't need a multiplexer, you can have a bunch of different USB root
> hubs in PCI slots, with USB hubs plugged into them, and lots of
> multi-port USB devices connected to them.  Tobias has such a system with
> 272 single-port USB to serial devices connected, so it's not impossible
> to create.
Correct. Since you can only have 127 devices on a single USB root-hub,
the trick is to spread the devices over many root-hubs. Most mainboards
already come with 3-5 root-hubs on-board and you of course can expand
that via pci/pcie cards, but be warned, for reasons beyond my
imagination, the XHCI specification lets the root-hub vendor decice on
how many devices it can support, so you could end up having XHCI
root-hubs that support lets say 20 devices.

> In thinking about it some more, I'll change that number to 500 for now,
> as it's a static array within the tty layer, and then work on making
> that dynamic so we don't have any limitations other than the number of
> minor numbers for a single major.
I also thought about it and I'd say 512 devices is about as high as I
would go in any real-world application, otherwise the fallout of a
broken system is slowly getting to big, depending on what you do over
the serial ports. Also 512 is a nice number. ;)

Tobias

Re: [PATCH 2/3] USB: serial: make minor allocation dynamic

[Greg KH]

On Thu, Jun 06, 2013 at 02:17:18PM +0200, Johan Hovold wrote:
> On Wed, Jun 05, 2013 at 10:54:55AM -0700, Greg KH wrote:
> > From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > 
> > 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>
> 
> [...]
> 
> > -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;
> 
> You could use SERIAL_TTY_NO_MINOR here -- if needed at all, as it has
> already been set in create_serial.
> 
> > +	for (i = 0; i < num_ports; ++i) {
> > +		x = get_free_port(serial->port[i]);
> > +		if (x < 0)
> > +			goto error;
> > +		if (*minor == 0xffffffff)
> > +			*minor = x;
> 
> We must not update *minor until all port minors have been allocated, or
> idr_remove might get called for unallocated minors or even minor numbers
> of other ports in return_serial when the serial struct is destroyed.

Good point.  In looking at this further, I really need to drop the
usb_serial structure's minor field completly, as it doesn't make sense
anymore.

I'll go rework all of that and post a v2 of this series, thanks.

> > +		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]->minor);
> > +	return x;
> 
> table_lock?

Good catch, now fixed.

> >  }
> >  
> >  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]->minor);
> >  	mutex_unlock(&table_lock);
> >  }
> >  
> 
> [...]
> 
> Looks good otherwise.

Thanks for the review, much appreciated.

greg k-h

Re: [PATCH 1/3] USB: serial: ports: add minor and port number

[Greg KH]

On Thu, Jun 06, 2013 at 01:31:06PM +0200, Johan Hovold wrote:
> On Wed, Jun 05, 2013 at 10:55:39AM -0700, Greg KH wrote:
> > From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > 
> > The usb_serial_port structure had the number field, which was the minor
> > number for the port, which almost no one really cared about.  They
> > really wanted the number of the port within the device, which you had to
> > subtract from the minor of the parent usb_serial_device structure.  To
> > clean this up, provide the real minor number of the port, and the number
> > of the port within the serial device separately, as these numbers might
> > not be related in the future.
> > 
> > Bonus is that this cleans up a lot of logic in the drivers, and saves
> > lines overall.
> > 
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> > --- a/drivers/usb/serial/io_edgeport.c
> > +++ b/drivers/usb/serial/io_edgeport.c
> 
> > @@ -2302,7 +2293,7 @@ static int send_cmd_write_baud_rate(stru
> >  
> >  	/* Restore original value to disable access to divisor latch */
> >  	MAKE_CMD_WRITE_REG(&currCmd, &cmdLen, number, LCR,
> > -						edge_port->shadowLCR);
> > +			   edge_port->shadowLCR);
> 
> Unintended indentation change?

Yeah, due to a previous change I made to this line, I'll go remove this,
thanks.

> >  	status = write_cmd_usb(edge_port, cmdBuffer, cmdLen);
> >  	if (status) {
> 
> > --- a/drivers/usb/serial/whiteheat.c
> > +++ b/drivers/usb/serial/whiteheat.c
> 
> > @@ -649,7 +649,7 @@ static void firm_setup_port(struct tty_s
> >  	struct whiteheat_port_settings port_settings;
> >  	unsigned int cflag = tty->termios.c_cflag;
> >  
> > -	port_settings.port = port->number + 1;
> > +	port_settings.port = port->port_number + 1;
> 
> This is a bug that should be fixed separately and backported, as it
> prevents port configuration (e.g. set_termios) for ports with minor
> number greater than 0.
> 
> I took the liberty to prepare a separate patch for v3.10, which you
> could rebase the series on.

Ah, I missed that, thanks, I've queued up your patch and rebased this
series on it now.

> > --- a/include/linux/usb/serial.h
> > +++ b/include/linux/usb/serial.h
> > @@ -37,7 +37,8 @@
> >   * @serial: pointer back to the struct usb_serial owner of this port.
> >   * @port: pointer to the corresponding tty_port for this port.
> >   * @lock: spinlock to grab when updating portions of this structure.
> > - * @number: the number of the port (the minor number).
> > + * @minor: the minor number of the port
> > + * @port_number: the port number of this struct usb_serial_device (starts at 0)
> 
> Maybe 
> 
> 	@port_number: the struct usb_serial port number of this port (starts at 0)
> 
> or something similar, would be more clear?

Yeah, much better, thanks.

greg k-h