aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/serial/usb-serial.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/usb/serial/usb-serial.c')
-rw-r--r--drivers/usb/serial/usb-serial.c408
1 files changed, 187 insertions, 221 deletions
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 99188c92068..ff75a3589e7 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -35,6 +35,7 @@
#include <linux/serial.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
+#include <linux/kfifo.h>
#include "pl2303.h"
/*
@@ -43,8 +44,6 @@
#define DRIVER_AUTHOR "Greg Kroah-Hartman, greg@kroah.com, http://www.kroah.com/linux/"
#define DRIVER_DESC "USB Serial Driver core"
-static void port_free(struct usb_serial_port *port);
-
/* Driver structure we register with the USB core */
static struct usb_driver usb_serial_driver = {
.name = "usbserial",
@@ -68,6 +67,11 @@ static struct usb_serial *serial_table[SERIAL_TTY_MINORS];
static DEFINE_MUTEX(table_lock);
static LIST_HEAD(usb_serial_driver_list);
+/*
+ * Look up the serial structure. If it is found and it hasn't been
+ * disconnected, return with its disc_mutex held and its refcount
+ * incremented. Otherwise return NULL.
+ */
struct usb_serial *usb_serial_get_by_index(unsigned index)
{
struct usb_serial *serial;
@@ -75,8 +79,15 @@ struct usb_serial *usb_serial_get_by_index(unsigned index)
mutex_lock(&table_lock);
serial = serial_table[index];
- if (serial)
- kref_get(&serial->kref);
+ if (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);
return serial;
}
@@ -125,8 +136,10 @@ static void return_serial(struct usb_serial *serial)
dbg("%s", __func__);
+ mutex_lock(&table_lock);
for (i = 0; i < serial->num_ports; ++i)
serial_table[serial->minor + i] = NULL;
+ mutex_unlock(&table_lock);
}
static void destroy_serial(struct kref *kref)
@@ -145,244 +158,224 @@ static void destroy_serial(struct kref *kref)
serial->type->release(serial);
- for (i = 0; i < serial->num_ports; ++i) {
+ /* Now that nothing is using the ports, they can be freed */
+ for (i = 0; i < serial->num_port_pointers; ++i) {
port = serial->port[i];
- if (port)
+ if (port) {
+ port->serial = NULL;
put_device(&port->dev);
- }
-
- /* If this is a "fake" port, we have to clean it up here, as it will
- * not get cleaned up in port_release() as it was never registered with
- * the driver core */
- if (serial->num_ports < serial->num_port_pointers) {
- for (i = serial->num_ports;
- i < serial->num_port_pointers; ++i) {
- port = serial->port[i];
- if (port)
- port_free(port);
}
}
usb_put_dev(serial->dev);
-
- /* free up any memory that we allocated */
kfree(serial);
}
void usb_serial_put(struct usb_serial *serial)
{
- mutex_lock(&table_lock);
kref_put(&serial->kref, destroy_serial);
- mutex_unlock(&table_lock);
}
/*****************************************************************************
* Driver tty interface functions
*****************************************************************************/
-static int serial_open (struct tty_struct *tty, struct file *filp)
+
+/**
+ * serial_install - install tty
+ * @driver: the driver (USB in our case)
+ * @tty: the tty being created
+ *
+ * Create the termios objects for this tty. We use the default
+ * USB serial settings but permit them to be overridden by
+ * serial->type->init_termios.
+ *
+ * This is the first place a new tty gets used. Hence this is where we
+ * acquire references to the usb_serial structure and the driver module,
+ * where we store a pointer to the port, and where we do an autoresume.
+ * All these actions are reversed in serial_release().
+ */
+static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
{
+ int idx = tty->index;
struct usb_serial *serial;
struct usb_serial_port *port;
- unsigned int portNumber;
- int retval = 0;
- int first = 0;
+ int retval = -ENODEV;
dbg("%s", __func__);
- /* get the serial object associated with this tty pointer */
- serial = usb_serial_get_by_index(tty->index);
- if (!serial) {
- tty->driver_data = NULL;
- return -ENODEV;
- }
+ serial = usb_serial_get_by_index(idx);
+ if (!serial)
+ return retval;
- mutex_lock(&serial->disc_mutex);
- portNumber = tty->index - serial->minor;
- port = serial->port[portNumber];
- if (!port || serial->disconnected)
- retval = -ENODEV;
- else
- get_device(&port->dev);
- /*
- * Note: Our locking order requirement does not allow port->mutex
- * to be acquired while serial->disc_mutex is held.
- */
- mutex_unlock(&serial->disc_mutex);
+ port = serial->port[idx - serial->minor];
+ if (!port)
+ goto error_no_port;
+ if (!try_module_get(serial->type->driver.owner))
+ goto error_module_get;
+
+ /* perform the standard setup */
+ retval = tty_init_termios(tty);
if (retval)
- goto bailout_serial_put;
+ goto error_init_termios;
- if (mutex_lock_interruptible(&port->mutex)) {
- retval = -ERESTARTSYS;
- goto bailout_port_put;
- }
+ retval = usb_autopm_get_interface(serial->interface);
+ if (retval)
+ goto error_get_interface;
- ++port->port.count;
+ mutex_unlock(&serial->disc_mutex);
+
+ /* allow the driver to update the settings */
+ if (serial->type->init_termios)
+ serial->type->init_termios(tty);
- /* set up our port structure making the tty driver
- * remember our port object, and us it */
tty->driver_data = port;
- tty_port_tty_set(&port->port, tty);
- /* If the console is attached, the device is already open */
- if (port->port.count == 1 && !port->console) {
- first = 1;
- /* lock this module before we call it
- * this may fail, which means we must bail out,
- * safe because we are called with BKL held */
- if (!try_module_get(serial->type->driver.owner)) {
- retval = -ENODEV;
- goto bailout_mutex_unlock;
- }
+ /* Final install (we use the default method) */
+ tty_driver_kref_get(driver);
+ tty->count++;
+ driver->ttys[idx] = tty;
+ return retval;
+
+ error_get_interface:
+ error_init_termios:
+ module_put(serial->type->driver.owner);
+ error_module_get:
+ error_no_port:
+ usb_serial_put(serial);
+ mutex_unlock(&serial->disc_mutex);
+ return retval;
+}
+static int serial_open(struct tty_struct *tty, struct file *filp)
+{
+ struct usb_serial_port *port = tty->driver_data;
+ struct usb_serial *serial = port->serial;
+ int retval;
+
+ dbg("%s - port %d", __func__, port->number);
+
+ spin_lock_irq(&port->port.lock);
+ if (!tty_hung_up_p(filp))
+ ++port->port.count;
+ spin_unlock_irq(&port->port.lock);
+ tty_port_tty_set(&port->port, tty);
+
+ /* Do the device-specific open only if the hardware isn't
+ * already initialized.
+ */
+ if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags)) {
+ if (mutex_lock_interruptible(&port->mutex))
+ return -ERESTARTSYS;
mutex_lock(&serial->disc_mutex);
if (serial->disconnected)
retval = -ENODEV;
else
- retval = usb_autopm_get_interface(serial->interface);
- if (retval)
- goto bailout_module_put;
-
- /* only call the device specific open if this
- * is the first time the port is opened */
- retval = serial->type->open(tty, port, filp);
- if (retval)
- goto bailout_interface_put;
+ retval = port->serial->type->open(tty, port);
mutex_unlock(&serial->disc_mutex);
+ mutex_unlock(&port->mutex);
+ if (retval)
+ return retval;
set_bit(ASYNCB_INITIALIZED, &port->port.flags);
}
- mutex_unlock(&port->mutex);
+
/* Now do the correct tty layer semantics */
retval = tty_port_block_til_ready(&port->port, tty, filp);
- if (retval == 0) {
- if (!first)
- usb_serial_put(serial);
- return 0;
- }
- mutex_lock(&port->mutex);
- if (first == 0)
- goto bailout_mutex_unlock;
- /* Undo the initial port actions */
- mutex_lock(&serial->disc_mutex);
-bailout_interface_put:
- usb_autopm_put_interface(serial->interface);
-bailout_module_put:
- mutex_unlock(&serial->disc_mutex);
- module_put(serial->type->driver.owner);
-bailout_mutex_unlock:
- port->port.count = 0;
- tty->driver_data = NULL;
- tty_port_tty_set(&port->port, NULL);
- mutex_unlock(&port->mutex);
-bailout_port_put:
- put_device(&port->dev);
-bailout_serial_put:
- usb_serial_put(serial);
return retval;
}
/**
- * serial_do_down - shut down hardware
- * @port: port to shut down
- *
- * Shut down a USB port unless it is the console. We never shut down the
- * console hardware as it will always be in use.
+ * serial_down - shut down hardware
+ * @port: port to shut down
*
- * Don't free any resources at this point
+ * Shut down a USB serial port unless it is the console. We never
+ * shut down the console hardware as it will always be in use.
*/
-static void serial_do_down(struct usb_serial_port *port)
+static void serial_down(struct usb_serial_port *port)
{
struct usb_serial_driver *drv = port->serial->type;
- struct usb_serial *serial;
- struct module *owner;
- /* The console is magical, do not hang up the console hardware
- or there will be tears */
+ /*
+ * The console is magical. Do not hang up the console hardware
+ * or there will be tears.
+ */
if (port->console)
return;
- mutex_lock(&port->mutex);
- serial = port->serial;
- owner = serial->type->driver.owner;
+ /* Don't call the close method if the hardware hasn't been
+ * initialized.
+ */
+ if (!test_and_clear_bit(ASYNCB_INITIALIZED, &port->port.flags))
+ return;
+ mutex_lock(&port->mutex);
if (drv->close)
drv->close(port);
-
mutex_unlock(&port->mutex);
}
-/**
- * serial_do_free - free resources post close/hangup
- * @port: port to free up
- *
- * Do the resource freeing and refcount dropping for the port. We must
- * be careful about ordering and we must avoid freeing up the console.
- */
-
-static void serial_do_free(struct usb_serial_port *port)
+static void serial_hangup(struct tty_struct *tty)
{
- struct usb_serial *serial;
- struct module *owner;
+ struct usb_serial_port *port = tty->driver_data;
- /* The console is magical, do not hang up the console hardware
- or there will be tears */
- if (port->console)
- return;
+ dbg("%s - port %d", __func__, port->number);
- serial = port->serial;
- owner = serial->type->driver.owner;
- put_device(&port->dev);
- /* Mustn't dereference port any more */
- mutex_lock(&serial->disc_mutex);
- if (!serial->disconnected)
- usb_autopm_put_interface(serial->interface);
- mutex_unlock(&serial->disc_mutex);
- usb_serial_put(serial);
- /* Mustn't dereference serial any more */
- module_put(owner);
+ serial_down(port);
+ tty_port_hangup(&port->port);
}
static void serial_close(struct tty_struct *tty, struct file *filp)
{
struct usb_serial_port *port = tty->driver_data;
- if (!port)
- return;
-
dbg("%s - port %d", __func__, port->number);
- /* FIXME:
- This leaves a very narrow race. Really we should do the
- serial_do_free() on tty->shutdown(), but tty->shutdown can
- be called from IRQ context and serial_do_free can sleep.
-
- The right fix is probably to make the tty free (which is rare)
- and thus tty->shutdown() occur via a work queue and simplify all
- the drivers that use it.
- */
- if (tty_hung_up_p(filp)) {
- /* serial_hangup already called serial_down at this point.
- Another user may have already reopened the port but
- serial_do_free is refcounted */
- serial_do_free(port);
+ if (tty_hung_up_p(filp))
return;
- }
-
if (tty_port_close_start(&port->port, tty, filp) == 0)
return;
-
- serial_do_down(port);
+ serial_down(port);
tty_port_close_end(&port->port, tty);
tty_port_tty_set(&port->port, NULL);
- serial_do_free(port);
}
-static void serial_hangup(struct tty_struct *tty)
+/**
+ * serial_release - free resources post close/hangup
+ * @port: port to free up
+ *
+ * Do the resource freeing and refcount dropping for the port.
+ * Avoid freeing the console.
+ *
+ * Called when the last tty kref is dropped.
+ */
+static void serial_release(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
- serial_do_down(port);
- tty_port_hangup(&port->port);
- /* We must not free port yet - the USB serial layer depends on it's
- continued existence */
+ struct usb_serial *serial;
+ struct module *owner;
+
+ /* The console is magical. Do not hang up the console hardware
+ * or there will be tears.
+ */
+ if (port->console)
+ return;
+
+ dbg("%s - port %d", __func__, port->number);
+
+ /* Standard shutdown processing */
+ tty_shutdown(tty);
+
+ tty->driver_data = NULL;
+
+ serial = port->serial;
+ owner = serial->type->driver.owner;
+
+ mutex_lock(&serial->disc_mutex);
+ if (!serial->disconnected)
+ usb_autopm_put_interface(serial->interface);
+ mutex_unlock(&serial->disc_mutex);
+
+ usb_serial_put(serial);
+ module_put(owner);
}
static int serial_write(struct tty_struct *tty, const unsigned char *buf,
@@ -527,6 +520,7 @@ static int serial_proc_show(struct seq_file *m, void *v)
seq_putc(m, '\n');
usb_serial_put(serial);
+ mutex_unlock(&serial->disc_mutex);
}
return 0;
}
@@ -596,14 +590,6 @@ static void usb_serial_port_work(struct work_struct *work)
tty_kref_put(tty);
}
-static void port_release(struct device *dev)
-{
- struct usb_serial_port *port = to_usb_serial_port(dev);
-
- dbg ("%s - %s", __func__, dev_name(dev));
- port_free(port);
-}
-
static void kill_traffic(struct usb_serial_port *port)
{
usb_kill_urb(port->read_urb);
@@ -623,8 +609,12 @@ static void kill_traffic(struct usb_serial_port *port)
usb_kill_urb(port->interrupt_out_urb);
}
-static void port_free(struct usb_serial_port *port)
+static void port_release(struct device *dev)
{
+ struct usb_serial_port *port = to_usb_serial_port(dev);
+
+ dbg ("%s - %s", __func__, dev_name(dev));
+
/*
* Stop all the traffic before cancelling the work, so that
* nobody will restart it by calling usb_serial_port_softint.
@@ -636,6 +626,8 @@ static void port_free(struct usb_serial_port *port)
usb_free_urb(port->write_urb);
usb_free_urb(port->interrupt_in_urb);
usb_free_urb(port->interrupt_out_urb);
+ if (!IS_ERR(port->write_fifo) && port->write_fifo)
+ kfifo_free(port->write_fifo);
kfree(port->bulk_in_buffer);
kfree(port->bulk_out_buffer);
kfree(port->interrupt_in_buffer);
@@ -935,6 +927,11 @@ int usb_serial_probe(struct usb_interface *interface,
mutex_init(&port->mutex);
INIT_WORK(&port->work, usb_serial_port_work);
serial->port[i] = port;
+ port->dev.parent = &interface->dev;
+ port->dev.driver = NULL;
+ port->dev.bus = &usb_serial_bus_type;
+ port->dev.release = &port_release;
+ device_initialize(&port->dev);
}
/* set up the endpoint information */
@@ -970,6 +967,10 @@ int usb_serial_probe(struct usb_interface *interface,
dev_err(&interface->dev, "No free urbs available\n");
goto probe_error;
}
+ port->write_fifo = kfifo_alloc(PAGE_SIZE, GFP_KERNEL,
+ &port->lock);
+ if (IS_ERR(port->write_fifo))
+ goto probe_error;
buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
port->bulk_out_size = buffer_size;
port->bulk_out_endpointAddress = endpoint->bEndpointAddress;
@@ -1077,15 +1078,10 @@ int usb_serial_probe(struct usb_interface *interface,
/* register all of the individual ports with the driver core */
for (i = 0; i < num_ports; ++i) {
port = serial->port[i];
- port->dev.parent = &interface->dev;
- port->dev.driver = NULL;
- port->dev.bus = &usb_serial_bus_type;
- port->dev.release = &port_release;
-
dev_set_name(&port->dev, "ttyUSB%d", port->number);
dbg ("%s - registering %s", __func__, dev_name(&port->dev));
port->dev_state = PORT_REGISTERING;
- retval = device_register(&port->dev);
+ retval = device_add(&port->dev);
if (retval) {
dev_err(&port->dev, "Error registering port device, "
"continuing\n");
@@ -1103,39 +1099,7 @@ exit:
return 0;
probe_error:
- for (i = 0; i < num_bulk_in; ++i) {
- port = serial->port[i];
- if (!port)
- continue;
- usb_free_urb(port->read_urb);
- kfree(port->bulk_in_buffer);
- }
- for (i = 0; i < num_bulk_out; ++i) {
- port = serial->port[i];
- if (!port)
- continue;
- usb_free_urb(port->write_urb);
- kfree(port->bulk_out_buffer);
- }
- for (i = 0; i < num_interrupt_in; ++i) {
- port = serial->port[i];
- if (!port)
- continue;
- usb_free_urb(port->interrupt_in_urb);
- kfree(port->interrupt_in_buffer);
- }
- for (i = 0; i < num_interrupt_out; ++i) {
- port = serial->port[i];
- if (!port)
- continue;
- usb_free_urb(port->interrupt_out_urb);
- kfree(port->interrupt_out_buffer);
- }
-
- /* free up any memory that we allocated */
- for (i = 0; i < serial->num_port_pointers; ++i)
- kfree(serial->port[i]);
- kfree(serial);
+ usb_serial_put(serial);
return -EIO;
}
EXPORT_SYMBOL_GPL(usb_serial_probe);
@@ -1161,10 +1125,7 @@ void usb_serial_disconnect(struct usb_interface *interface)
if (port) {
struct tty_struct *tty = tty_port_tty_get(&port->port);
if (tty) {
- /* The hangup will occur asynchronously but
- the object refcounts will sort out all the
- cleanup */
- tty_hangup(tty);
+ tty_vhangup(tty);
tty_kref_put(tty);
}
kill_traffic(port);
@@ -1189,8 +1150,7 @@ void usb_serial_disconnect(struct usb_interface *interface)
}
serial->type->disconnect(serial);
- /* let the last holder of this object
- * cause it to be cleaned up */
+ /* let the last holder of this object cause it to be cleaned up */
usb_serial_put(serial);
dev_info(dev, "device disconnected\n");
}
@@ -1204,15 +1164,19 @@ int usb_serial_suspend(struct usb_interface *intf, pm_message_t message)
serial->suspending = 1;
+ if (serial->type->suspend) {
+ r = serial->type->suspend(serial, message);
+ if (r < 0)
+ goto err_out;
+ }
+
for (i = 0; i < serial->num_ports; ++i) {
port = serial->port[i];
if (port)
kill_traffic(port);
}
- if (serial->type->suspend)
- r = serial->type->suspend(serial, message);
-
+err_out:
return r;
}
EXPORT_SYMBOL(usb_serial_suspend);
@@ -1246,6 +1210,8 @@ static const struct tty_operations serial_ops = {
.chars_in_buffer = serial_chars_in_buffer,
.tiocmget = serial_tiocmget,
.tiocmset = serial_tiocmset,
+ .shutdown = serial_release,
+ .install = serial_install,
.proc_fops = &serial_proc_fops,
};