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Commit 58801a2a authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
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[PATCH] USB serial: fix locking logic 

This gets rid of the port semaphore, and the serialization caused by
that, and replaces it with the proper reference counting logic for
the usb serial object.
parent 6428737c
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Showing with 86 additions and 98 deletions
drivers/usb/serial/console.c
View file @ 58801a2a
......@@ -141,7 +141,6 @@ static int __init usb_console_setup(struct console *co, char *options)
}
port = &serial->port[0];
down (&port->sem);
port->tty = NULL;
info->port = port;
......@@ -158,8 +157,6 @@ static int __init usb_console_setup(struct console *co, char *options)
port->open_count = 0;
}
up (&port->sem);
if (retval) {
err ("could not open USB console port");
return retval;
......@@ -208,8 +205,6 @@ static void usb_console_write(struct console *co, const char *buf, unsigned coun
if (count == 0)
return;
down (&port->sem);
dbg("%s - port %d, %d byte(s)", __FUNCTION__, port->number, count);
if (!port->open_count) {
......@@ -224,7 +219,6 @@ static void usb_console_write(struct console *co, const char *buf, unsigned coun
retval = usb_serial_generic_write(port, 0, buf, count);
exit:
up (&port->sem);
dbg("%s - return value (if we had one): %d", __FUNCTION__, retval);
}
......
drivers/usb/serial/usb-serial.c
View file @ 58801a2a
......@@ -391,7 +391,11 @@ static LIST_HEAD(usb_serial_driver_list);
struct usb_serial *usb_serial_get_by_minor (unsigned int minor)
{
return serial_table[minor];
struct usb_serial *serial = serial_table[minor];
if (serial)
kobject_get (&serial->kobj);
return serial;
}
static struct usb_serial *get_free_serial (struct usb_serial *serial, int num_ports, unsigned int *minor)
......@@ -468,7 +472,6 @@ static int serial_open (struct tty_struct *tty, struct file * filp)
port = &serial->port[portNumber];
tty->driver_data = port;
down (&port->sem);
port->tty = tty;
/* lock this module before we call it,
......@@ -492,8 +495,6 @@ static int serial_open (struct tty_struct *tty, struct file * filp)
}
}
bailout:
up (&port->sem);
return retval;
}
......@@ -516,6 +517,7 @@ static void __serial_close(struct usb_serial_port *port, struct file *filp)
}
module_put(port->serial->type->owner);
kobject_put(&port->serial->kobj);
}
static void serial_close(struct tty_struct *tty, struct file * filp)
......@@ -526,16 +528,12 @@ static void serial_close(struct tty_struct *tty, struct file * filp)
if (!serial)
return;
down (&port->sem);
dbg("%s - port %d", __FUNCTION__, port->number);
/* if disconnect beat us to the punch here, there's nothing to do */
if (tty->driver_data) {
__serial_close(port, filp);
}
up (&port->sem);
}
static int serial_write (struct tty_struct * tty, int from_user, const unsigned char *buf, int count)
......@@ -547,8 +545,6 @@ static int serial_write (struct tty_struct * tty, int from_user, const unsigned
if (!serial)
return -ENODEV;
down (&port->sem);
dbg("%s - port %d, %d byte(s)", __FUNCTION__, port->number, count);
if (!port->open_count) {
......@@ -563,7 +559,6 @@ static int serial_write (struct tty_struct * tty, int from_user, const unsigned
retval = usb_serial_generic_write(port, from_user, buf, count);
exit:
up (&port->sem);
return retval;
}
......@@ -576,8 +571,6 @@ static int serial_write_room (struct tty_struct *tty)
if (!serial)
return -ENODEV;
down (&port->sem);
dbg("%s - port %d", __FUNCTION__, port->number);
if (!port->open_count) {
......@@ -592,7 +585,6 @@ static int serial_write_room (struct tty_struct *tty)
retval = usb_serial_generic_write_room(port);
exit:
up (&port->sem);
return retval;
}
......@@ -605,8 +597,6 @@ static int serial_chars_in_buffer (struct tty_struct *tty)
if (!serial)
return -ENODEV;
down (&port->sem);
dbg("%s = port %d", __FUNCTION__, port->number);
if (!port->open_count) {
......@@ -621,7 +611,6 @@ static int serial_chars_in_buffer (struct tty_struct *tty)
retval = usb_serial_generic_chars_in_buffer(port);
exit:
up (&port->sem);
return retval;
}
......@@ -633,8 +622,6 @@ static void serial_throttle (struct tty_struct * tty)
if (!serial)
return;
down (&port->sem);
dbg("%s - port %d", __FUNCTION__, port->number);
if (!port->open_count) {
......@@ -647,7 +634,6 @@ static void serial_throttle (struct tty_struct * tty)
serial->type->throttle(port);
exit:
up (&port->sem);
}
static void serial_unthrottle (struct tty_struct * tty)
......@@ -658,8 +644,6 @@ static void serial_unthrottle (struct tty_struct * tty)
if (!serial)
return;
down (&port->sem);
dbg("%s - port %d", __FUNCTION__, port->number);
if (!port->open_count) {
......@@ -672,7 +656,6 @@ static void serial_unthrottle (struct tty_struct * tty)
serial->type->unthrottle(port);
exit:
up (&port->sem);
}
static int serial_ioctl (struct tty_struct *tty, struct file * file, unsigned int cmd, unsigned long arg)
......@@ -684,8 +667,6 @@ static int serial_ioctl (struct tty_struct *tty, struct file * file, unsigned in
if (!serial)
return -ENODEV;
down (&port->sem);
dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);
if (!port->open_count) {
......@@ -700,7 +681,6 @@ static int serial_ioctl (struct tty_struct *tty, struct file * file, unsigned in
retval = -ENOIOCTLCMD;
exit:
up (&port->sem);
return retval;
}
......@@ -712,8 +692,6 @@ static void serial_set_termios (struct tty_struct *tty, struct termios * old)
if (!serial)
return;
down (&port->sem);
dbg("%s - port %d", __FUNCTION__, port->number);
if (!port->open_count) {
......@@ -726,7 +704,6 @@ static void serial_set_termios (struct tty_struct *tty, struct termios * old)
serial->type->set_termios(port, old);
exit:
up (&port->sem);
}
static void serial_break (struct tty_struct *tty, int break_state)
......@@ -737,8 +714,6 @@ static void serial_break (struct tty_struct *tty, int break_state)
if (!serial)
return;
down (&port->sem);
dbg("%s - port %d", __FUNCTION__, port->number);
if (!port->open_count) {
......@@ -751,7 +726,6 @@ static void serial_break (struct tty_struct *tty, int break_state)
serial->type->break_ctl(port, break_state);
exit:
up (&port->sem);
}
static void serial_shutdown (struct usb_serial *serial)
......@@ -797,6 +771,7 @@ static int serial_read_proc (char *page, char **start, off_t off, int count, int
begin += length;
length = 0;
}
kobject_put(&serial->kobj);
}
*eof = 1;
done:
......@@ -833,6 +808,75 @@ void usb_serial_port_softint(void *private)
wake_up_interruptible(&tty->write_wait);
}
static void destroy_serial (struct kobject *kobj)
{
struct usb_serial *serial;
struct usb_serial_port *port;
int i;
dbg ("%s", __FUNCTION__);
serial = to_usb_serial(kobj);
/* fail all future close/read/write/ioctl/etc calls */
for (i = 0; i < serial->num_ports; ++i) {
port = &serial->port[i];
if (port->tty != NULL) {
port->tty->driver_data = NULL;
while (port->open_count > 0) {
__serial_close(port, NULL);
}
}
}
usb_put_dev(serial->dev);
serial->dev = NULL;
serial_shutdown (serial);
for (i = 0; i < serial->num_ports; ++i)
device_unregister(&serial->port[i].dev);
for (i = 0; i < serial->num_ports; ++i)
serial->port[i].open_count = 0;
for (i = 0; i < serial->num_bulk_in; ++i) {
port = &serial->port[i];
if (port->read_urb) {
usb_unlink_urb (port->read_urb);
usb_free_urb (port->read_urb);
}
if (port->bulk_in_buffer)
kfree (port->bulk_in_buffer);
}
for (i = 0; i < serial->num_bulk_out; ++i) {
port = &serial->port[i];
if (port->write_urb) {
usb_unlink_urb (port->write_urb);
usb_free_urb (port->write_urb);
}
if (port->bulk_out_buffer)
kfree (port->bulk_out_buffer);
}
for (i = 0; i < serial->num_interrupt_in; ++i) {
port = &serial->port[i];
if (port->interrupt_in_urb) {
usb_unlink_urb (port->interrupt_in_urb);
usb_free_urb (port->interrupt_in_urb);
}
if (port->interrupt_in_buffer)
kfree (port->interrupt_in_buffer);
}
/* return the minor range that this device had */
return_serial (serial);
/* free up any memory that we allocated */
kfree (serial);
}
static struct kobj_type usb_serial_kobj_type = {
.release = destroy_serial,
};
static struct usb_serial * create_serial (struct usb_device *dev,
struct usb_interface *interface,
struct usb_serial_device_type *type)
......@@ -845,12 +889,16 @@ static struct usb_serial * create_serial (struct usb_device *dev,
return NULL;
}
memset (serial, 0, sizeof(*serial));
serial->dev = dev;
serial->dev = usb_get_dev(dev);
serial->type = type;
serial->interface = interface;
serial->vendor = dev->descriptor.idVendor;
serial->product = dev->descriptor.idProduct;
/* initialize the kobject portion of the usb_device */
kobject_init(&serial->kobj);
serial->kobj.ktype = &usb_serial_kobj_type;
return serial;
}
......@@ -1113,7 +1161,6 @@ int usb_serial_probe(struct usb_interface *interface,
port->serial = serial;
port->magic = USB_SERIAL_PORT_MAGIC;
INIT_WORK(&port->work, usb_serial_port_softint, port);
init_MUTEX (&port->sem);
}
/* if this device type has an attach function, call it */
......@@ -1189,67 +1236,14 @@ void usb_serial_disconnect(struct usb_interface *interface)
{
struct usb_serial *serial = usb_get_intfdata (interface);
struct device *dev = &interface->dev;
struct usb_serial_port *port;
int i;
dbg ("%s", __FUNCTION__);
usb_set_intfdata (interface, NULL);
if (serial) {
/* fail all future close/read/write/ioctl/etc calls */
for (i = 0; i < serial->num_ports; ++i) {
port = &serial->port[i];
down (&port->sem);
if (port->tty != NULL) {
port->tty->driver_data = NULL;
while (port->open_count > 0) {
__serial_close(port, NULL);
}
}
up (&port->sem);
}
serial->dev = NULL;
serial_shutdown (serial);
for (i = 0; i < serial->num_ports; ++i)
device_unregister(&serial->port[i].dev);
for (i = 0; i < serial->num_ports; ++i)
serial->port[i].open_count = 0;
for (i = 0; i < serial->num_bulk_in; ++i) {
port = &serial->port[i];
if (port->read_urb) {
usb_unlink_urb (port->read_urb);
usb_free_urb (port->read_urb);
}
if (port->bulk_in_buffer)
kfree (port->bulk_in_buffer);
}
for (i = 0; i < serial->num_bulk_out; ++i) {
port = &serial->port[i];
if (port->write_urb) {
usb_unlink_urb (port->write_urb);
usb_free_urb (port->write_urb);
}
if (port->bulk_out_buffer)
kfree (port->bulk_out_buffer);
}
for (i = 0; i < serial->num_interrupt_in; ++i) {
port = &serial->port[i];
if (port->interrupt_in_urb) {
usb_unlink_urb (port->interrupt_in_urb);
usb_free_urb (port->interrupt_in_urb);
}
if (port->interrupt_in_buffer)
kfree (port->interrupt_in_buffer);
}
/* return the minor range that this device had */
return_serial (serial);
/* free up any memory that we allocated */
kfree (serial);
/* let the last holder of this object
* cause it to be cleaned up */
kobject_put (&serial->kobj);
}
dev_info(dev, "device disconnected\n");
}
......
drivers/usb/serial/usb-serial.h
View file @ 58801a2a
......@@ -89,7 +89,6 @@
* @write_wait: a wait_queue_head_t used by the port.
* @work: work queue entry for the line discipline waking up.
* @open_count: number of times this port has been opened.
* @sem: struct semaphore used to lock this structure.
*
* This structure is used by the usb-serial core and drivers for the specific
* ports of a device.
......@@ -116,7 +115,6 @@ struct usb_serial_port {
wait_queue_head_t write_wait;
struct work_struct work;
int open_count;
struct semaphore sem;
struct device dev;
};
#define to_usb_serial_port(d) container_of(d, struct usb_serial_port, dev)
......@@ -164,8 +162,10 @@ struct usb_serial {
__u16 vendor;
__u16 product;
struct usb_serial_port port[MAX_NUM_PORTS];
struct kobject kobj;
void * private;
};
#define to_usb_serial(d) container_of(d, struct usb_serial, kobj)
#define NUM_DONT_CARE (-1)
......
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