1 files changed, 188 insertions, 138 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index e8c564a53346..3027ada1b812 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -58,12 +58,64 @@ static struct usb_driver acm_driver;
 static struct tty_driver *acm_tty_driver;
 static struct acm *acm_table[ACM_TTY_MINORS];
 
-static DEFINE_MUTEX(open_mutex);
+static DEFINE_MUTEX(acm_table_lock);
 
 #define ACM_READY(acm)  (acm && acm->dev && acm->port.count)
 
-static const struct tty_port_operations acm_port_ops = {
-};
+/*
+ * acm_table accessors
+ */
+
+/*
+ * Look up an ACM structure by index. If found and not disconnected, increment
+ * its refcount and return it with its mutex held.
+ */
+static struct acm *acm_get_by_index(unsigned index)
+{
+        struct acm *acm;
+
+        mutex_lock(&acm_table_lock);
+        acm = acm_table[index];
+        if (acm) {
+                mutex_lock(&acm->mutex);
+                if (acm->disconnected) {
+                        mutex_unlock(&acm->mutex);
+                        acm = NULL;
+                } else {
+                        tty_port_get(&acm->port);
+                        mutex_unlock(&acm->mutex);
+                }
+        }
+        mutex_unlock(&acm_table_lock);
+        return acm;
+}
+
+/*
+ * Try to find an available minor number and if found, associate it with 'acm'.
+ */
+static int acm_alloc_minor(struct acm *acm)
+{
+        int minor;
+
+        mutex_lock(&acm_table_lock);
+        for (minor = 0; minor < ACM_TTY_MINORS; minor++) {
+                if (!acm_table[minor]) {
+                        acm_table[minor] = acm;
+                        break;
+                }
+        }
+        mutex_unlock(&acm_table_lock);
+
+        return minor;
+}
+
+/* Release the minor number associated with 'acm'.  */
+static void acm_release_minor(struct acm *acm)
+{
+        mutex_lock(&acm_table_lock);
+        acm_table[acm->minor] = NULL;
+        mutex_unlock(&acm_table_lock);
+}
 
 /*
  * Functions for ACM control messages.
@@ -453,93 +505,122 @@ static void acm_softint(struct work_struct *work)
  * TTY handlers
  */
 
-static int acm_tty_open(struct tty_struct *tty, struct file *filp)
+static int acm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
 {
         struct acm *acm;
-        int rv = -ENODEV;
-
-        mutex_lock(&open_mutex);
+        int retval;
 
-        acm = acm_table[tty->index];
-        if (!acm || !acm->dev)
-                goto out;
-        else
-                rv = 0;
+        dev_dbg(tty->dev, "%s\n", __func__);
 
-        dev_dbg(&acm->control->dev, "%s\n", __func__);
+        acm = acm_get_by_index(tty->index);
+        if (!acm)
+                return -ENODEV;
 
-        set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
+        retval = tty_init_termios(tty);
+        if (retval)
+                goto error_init_termios;
 
         tty->driver_data = acm;
-        tty_port_tty_set(&acm->port, tty);
 
-        if (usb_autopm_get_interface(acm->control) < 0)
-                goto early_bail;
-        else
-                acm->control->needs_remote_wakeup = 1;
+        /* Final install (we use the default method) */
+        tty_driver_kref_get(driver);
+        tty->count++;
+        driver->ttys[tty->index] = tty;
+
+        return 0;
+
+error_init_termios:
+        tty_port_put(&acm->port);
+        return retval;
+}
+
+static int acm_tty_open(struct tty_struct *tty, struct file *filp)
+{
+        struct acm *acm = tty->driver_data;
+
+        dev_dbg(tty->dev, "%s\n", __func__);
+
+        return tty_port_open(&acm->port, tty, filp);
+}
+
+static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
+{
+        struct acm *acm = container_of(port, struct acm, port);
+        int retval = -ENODEV;
+
+        dev_dbg(&acm->control->dev, "%s\n", __func__);
 
         mutex_lock(&acm->mutex);
-        if (acm->port.count++) {
-                mutex_unlock(&acm->mutex);
-                usb_autopm_put_interface(acm->control);
-                goto out;
-        }
+        if (acm->disconnected)
+                goto disconnected;
+
+        retval = usb_autopm_get_interface(acm->control);
+        if (retval)
+                goto error_get_interface;
+
+        /*
+         * FIXME: Why do we need this? Allocating 64K of physically contiguous
+         * memory is really nasty...
+         */
+        set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
+        acm->control->needs_remote_wakeup = 1;
 
         acm->ctrlurb->dev = acm->dev;
         if (usb_submit_urb(acm->ctrlurb, GFP_KERNEL)) {
                 dev_err(&acm->control->dev,
                         "%s - usb_submit_urb(ctrl irq) failed\n", __func__);
-                goto bail_out;
+                goto error_submit_urb;
         }
 
-        if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS) &&
+        acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS;
+        if (acm_set_control(acm, acm->ctrlout) < 0 &&
             (acm->ctrl_caps & USB_CDC_CAP_LINE))
-                goto bail_out;
+                goto error_set_control;
 
         usb_autopm_put_interface(acm->control);
 
         if (acm_submit_read_urbs(acm, GFP_KERNEL))
-                goto bail_out;
-
-        set_bit(ASYNCB_INITIALIZED, &acm->port.flags);
-        rv = tty_port_block_til_ready(&acm->port, tty, filp);
+                goto error_submit_read_urbs;
 
         mutex_unlock(&acm->mutex);
-out:
-        mutex_unlock(&open_mutex);
-        return rv;
 
-bail_out:
-        acm->port.count--;
-        mutex_unlock(&acm->mutex);
+        return 0;
+
+error_submit_read_urbs:
+        acm->ctrlout = 0;
+        acm_set_control(acm, acm->ctrlout);
+error_set_control:
+        usb_kill_urb(acm->ctrlurb);
+error_submit_urb:
         usb_autopm_put_interface(acm->control);
-early_bail:
-        mutex_unlock(&open_mutex);
-        tty_port_tty_set(&acm->port, NULL);
-        return -EIO;
+error_get_interface:
+disconnected:
+        mutex_unlock(&acm->mutex);
+        return retval;
 }
 
-static void acm_tty_unregister(struct acm *acm)
+static void acm_port_destruct(struct tty_port *port)
 {
-        int i;
+        struct acm *acm = container_of(port, struct acm, port);
+
+        dev_dbg(&acm->control->dev, "%s\n", __func__);
 
         tty_unregister_device(acm_tty_driver, acm->minor);
+        acm_release_minor(acm);
         usb_put_intf(acm->control);
-        acm_table[acm->minor] = NULL;
-        usb_free_urb(acm->ctrlurb);
-        for (i = 0; i < ACM_NW; i++)
-                usb_free_urb(acm->wb[i].urb);
-        for (i = 0; i < acm->rx_buflimit; i++)
-                usb_free_urb(acm->read_urbs[i]);
         kfree(acm->country_codes);
         kfree(acm);
 }
 
-static void acm_port_down(struct acm *acm)
+static void acm_port_shutdown(struct tty_port *port)
 {
+        struct acm *acm = container_of(port, struct acm, port);
         int i;
 
-        if (acm->dev) {
+        dev_dbg(&acm->control->dev, "%s\n", __func__);
+
+        mutex_lock(&acm->mutex);
+        if (!acm->disconnected) {
                 usb_autopm_get_interface(acm->control);
                 acm_set_control(acm, acm->ctrlout = 0);
                 usb_kill_urb(acm->ctrlurb);
@@ -550,40 +631,28 @@ static void acm_port_down(struct acm *acm)
                 acm->control->needs_remote_wakeup = 0;
                 usb_autopm_put_interface(acm->control);
         }
+        mutex_unlock(&acm->mutex);
+}
+
+static void acm_tty_cleanup(struct tty_struct *tty)
+{
+        struct acm *acm = tty->driver_data;
+        dev_dbg(&acm->control->dev, "%s\n", __func__);
+        tty_port_put(&acm->port);
 }
 
 static void acm_tty_hangup(struct tty_struct *tty)
 {
         struct acm *acm = tty->driver_data;
+        dev_dbg(&acm->control->dev, "%s\n", __func__);
         tty_port_hangup(&acm->port);
-        mutex_lock(&open_mutex);
-        acm_port_down(acm);
-        mutex_unlock(&open_mutex);
 }
 
 static void acm_tty_close(struct tty_struct *tty, struct file *filp)
 {
         struct acm *acm = tty->driver_data;
-
-        /* Perform the closing process and see if we need to do the hardware
-           shutdown */
-        if (!acm)
-                return;
-
-        mutex_lock(&open_mutex);
-        if (tty_port_close_start(&acm->port, tty, filp) == 0) {
-                if (!acm->dev) {
-                        tty_port_tty_set(&acm->port, NULL);
-                        acm_tty_unregister(acm);
-                        tty->driver_data = NULL;
-                }
-                mutex_unlock(&open_mutex);
-                return;
-        }
-        acm_port_down(acm);
-        tty_port_close_end(&acm->port, tty);
-        tty_port_tty_set(&acm->port, NULL);
-        mutex_unlock(&open_mutex);
+        dev_dbg(&acm->control->dev, "%s\n", __func__);
+        tty_port_close(&acm->port, tty, filp);
 }
 
 static int acm_tty_write(struct tty_struct *tty,
@@ -595,8 +664,6 @@ static int acm_tty_write(struct tty_struct *tty,
         int wbn;
         struct acm_wb *wb;
 
-        if (!ACM_READY(acm))
-                return -EINVAL;
         if (!count)
                 return 0;
 
@@ -625,8 +692,6 @@ static int acm_tty_write(struct tty_struct *tty,
 static int acm_tty_write_room(struct tty_struct *tty)
 {
         struct acm *acm = tty->driver_data;
-        if (!ACM_READY(acm))
-                return -EINVAL;
         /*
          * Do not let the line discipline to know that we have a reserve,
          * or it might get too enthusiastic.
@@ -637,7 +702,11 @@ static int acm_tty_write_room(struct tty_struct *tty)
 static int acm_tty_chars_in_buffer(struct tty_struct *tty)
 {
         struct acm *acm = tty->driver_data;
-        if (!ACM_READY(acm))
+        /*
+         * if the device was unplugged then any remaining characters fell out
+         * of the connector ;)
+         */
+        if (acm->disconnected)
                 return 0;
         /*
          * This is inaccurate (overcounts), but it works.
@@ -649,9 +718,6 @@ static void acm_tty_throttle(struct tty_struct *tty)
 {
         struct acm *acm = tty->driver_data;
 
-        if (!ACM_READY(acm))
-                return;
-
         spin_lock_irq(&acm->read_lock);
         acm->throttle_req = 1;
         spin_unlock_irq(&acm->read_lock);
@@ -662,9 +728,6 @@ static void acm_tty_unthrottle(struct tty_struct *tty)
         struct acm *acm = tty->driver_data;
         unsigned int was_throttled;
 
-        if (!ACM_READY(acm))
-                return;
-
         spin_lock_irq(&acm->read_lock);
         was_throttled = acm->throttled;
         acm->throttled = 0;
@@ -679,8 +742,7 @@ static int acm_tty_break_ctl(struct tty_struct *tty, int state)
 {
         struct acm *acm = tty->driver_data;
         int retval;
-        if (!ACM_READY(acm))
-                return -EINVAL;
+
         retval = acm_send_break(acm, state ? 0xffff : 0);
         if (retval < 0)
                 dev_dbg(&acm->control->dev, "%s - send break failed\n",
@@ -692,9 +754,6 @@ static int acm_tty_tiocmget(struct tty_struct *tty)
 {
         struct acm *acm = tty->driver_data;
 
-        if (!ACM_READY(acm))
-                return -EINVAL;
-
         return (acm->ctrlout & ACM_CTRL_DTR ? TIOCM_DTR : 0) |
                (acm->ctrlout & ACM_CTRL_RTS ? TIOCM_RTS : 0) |
                (acm->ctrlin  & ACM_CTRL_DSR ? TIOCM_DSR : 0) |
@@ -709,9 +768,6 @@ static int acm_tty_tiocmset(struct tty_struct *tty,
         struct acm *acm = tty->driver_data;
         unsigned int newctrl;
 
-        if (!ACM_READY(acm))
-                return -EINVAL;
-
         newctrl = acm->ctrlout;
         set = (set & TIOCM_DTR ? ACM_CTRL_DTR : 0) |
                                         (set & TIOCM_RTS ? ACM_CTRL_RTS : 0);
@@ -728,11 +784,6 @@ static int acm_tty_tiocmset(struct tty_struct *tty,
 static int acm_tty_ioctl(struct tty_struct *tty,
                                         unsigned int cmd, unsigned long arg)
 {
-        struct acm *acm = tty->driver_data;
-
-        if (!ACM_READY(acm))
-                return -EINVAL;
-
         return -ENOIOCTLCMD;
 }
 
@@ -756,9 +807,6 @@ static void acm_tty_set_termios(struct tty_struct *tty,
         struct usb_cdc_line_coding newline;
         int newctrl = acm->ctrlout;
 
-        if (!ACM_READY(acm))
-                return;
-
         newline.dwDTERate = cpu_to_le32(tty_get_baud_rate(tty));
         newline.bCharFormat = termios->c_cflag & CSTOPB ? 2 : 0;
         newline.bParityType = termios->c_cflag & PARENB ?
@@ -788,6 +836,12 @@ static void acm_tty_set_termios(struct tty_struct *tty,
         }
 }
 
+static const struct tty_port_operations acm_port_ops = {
+        .shutdown = acm_port_shutdown,
+        .activate = acm_port_activate,
+        .destruct = acm_port_destruct,
+};
+
 /*
  * USB probe and disconnect routines.
  */
@@ -1047,12 +1101,6 @@ skip_normal_probe:
         }
 made_compressed_probe:
         dev_dbg(&intf->dev, "interfaces are valid\n");
-        for (minor = 0; minor < ACM_TTY_MINORS && acm_table[minor]; minor++);
-
-        if (minor == ACM_TTY_MINORS) {
-                dev_err(&intf->dev, "no more free acm devices\n");
-                return -ENODEV;
-        }
 
         acm = kzalloc(sizeof(struct acm), GFP_KERNEL);
         if (acm == NULL) {
@@ -1060,6 +1108,13 @@ made_compressed_probe:
                 goto alloc_fail;
         }
 
+        minor = acm_alloc_minor(acm);
+        if (minor == ACM_TTY_MINORS) {
+                dev_err(&intf->dev, "no more free acm devices\n");
+                kfree(acm);
+                return -ENODEV;
+        }
+
         ctrlsize = usb_endpoint_maxp(epctrl);
         readsize = usb_endpoint_maxp(epread) *
                                 (quirks == SINGLE_RX_URB ? 1 : 2);
@@ -1218,8 +1273,6 @@ skip_countries:
         usb_get_intf(control_interface);
         tty_register_device(acm_tty_driver, minor, &control_interface->dev);
 
-        acm_table[minor] = acm;
-
         return 0;
 alloc_fail7:
         for (i = 0; i < ACM_NW; i++)
@@ -1234,6 +1287,7 @@ alloc_fail5:
 alloc_fail4:
         usb_free_coherent(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
 alloc_fail2:
+        acm_release_minor(acm);
         kfree(acm);
 alloc_fail:
         return -ENOMEM;
@@ -1259,12 +1313,16 @@ static void acm_disconnect(struct usb_interface *intf)
         struct acm *acm = usb_get_intfdata(intf);
         struct usb_device *usb_dev = interface_to_usbdev(intf);
         struct tty_struct *tty;
+        int i;
+
+        dev_dbg(&intf->dev, "%s\n", __func__);
 
         /* sibling interface is already cleaning up */
         if (!acm)
                 return;
 
-        mutex_lock(&open_mutex);
+        mutex_lock(&acm->mutex);
+        acm->disconnected = true;
         if (acm->country_codes) {
                 device_remove_file(&acm->control->dev,
                                 &dev_attr_wCountryCodes);
@@ -1272,33 +1330,32 @@ static void acm_disconnect(struct usb_interface *intf)
                                 &dev_attr_iCountryCodeRelDate);
         }
         device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
-        acm->dev = NULL;
         usb_set_intfdata(acm->control, NULL);
         usb_set_intfdata(acm->data, NULL);
+        mutex_unlock(&acm->mutex);
+
+        tty = tty_port_tty_get(&acm->port);
+        if (tty) {
+                tty_vhangup(tty);
+                tty_kref_put(tty);
+        }
 
         stop_data_traffic(acm);
 
+        usb_free_urb(acm->ctrlurb);
+        for (i = 0; i < ACM_NW; i++)
+                usb_free_urb(acm->wb[i].urb);
+        for (i = 0; i < acm->rx_buflimit; i++)
+                usb_free_urb(acm->read_urbs[i]);
         acm_write_buffers_free(acm);
-        usb_free_coherent(usb_dev, acm->ctrlsize, acm->ctrl_buffer,
-                          acm->ctrl_dma);
+        usb_free_coherent(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
         acm_read_buffers_free(acm);
 
         if (!acm->combined_interfaces)
                 usb_driver_release_interface(&acm_driver, intf == acm->control ?
                                         acm->data : acm->control);
 
-        if (acm->port.count == 0) {
-                acm_tty_unregister(acm);
-                mutex_unlock(&open_mutex);
-                return;
-        }
-
-        mutex_unlock(&open_mutex);
-        tty = tty_port_tty_get(&acm->port);
-        if (tty) {
-                tty_hangup(tty);
-                tty_kref_put(tty);
-        }
+        tty_port_put(&acm->port);
 }
 
 #ifdef CONFIG_PM
@@ -1325,16 +1382,10 @@ static int acm_suspend(struct usb_interface *intf, pm_message_t message)
 
         if (cnt)
                 return 0;
-        /*
-        we treat opened interfaces differently,
-        we must guard against open
-        */
-        mutex_lock(&acm->mutex);
 
-        if (acm->port.count)
+        if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags))
                 stop_data_traffic(acm);
 
-        mutex_unlock(&acm->mutex);
         return 0;
 }
 
@@ -1353,8 +1404,7 @@ static int acm_resume(struct usb_interface *intf)
         if (cnt)
                 return 0;
 
-        mutex_lock(&acm->mutex);
-        if (acm->port.count) {
+        if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags)) {
                 rv = usb_submit_urb(acm->ctrlurb, GFP_NOIO);
 
                 spin_lock_irq(&acm->write_lock);
@@ -1378,7 +1428,6 @@ static int acm_resume(struct usb_interface *intf)
         }
 
 err_out:
-        mutex_unlock(&acm->mutex);
         return rv;
 }
 
@@ -1387,15 +1436,14 @@ static int acm_reset_resume(struct usb_interface *intf)
         struct acm *acm = usb_get_intfdata(intf);
         struct tty_struct *tty;
 
-        mutex_lock(&acm->mutex);
-        if (acm->port.count) {
+        if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags)) {
                 tty = tty_port_tty_get(&acm->port);
                 if (tty) {
                         tty_hangup(tty);
                         tty_kref_put(tty);
                 }
         }
-        mutex_unlock(&acm->mutex);
+
         return acm_resume(intf);
 }
 
@@ -1594,8 +1642,10 @@ static struct usb_driver acm_driver = {
  */
 
 static const struct tty_operations acm_ops = {
+        .install =              acm_tty_install,
         .open =                 acm_tty_open,
         .close =                acm_tty_close,
+        .cleanup =              acm_tty_cleanup,
         .hangup =               acm_tty_hangup,
         .write =                acm_tty_write,
         .write_room =           acm_tty_write_room,