USB: whiteheat driver update

this is an update of the whiteheat driver. It fixes:

- switch from spinlocks to mutexes to prevent sleeping with a spinlock held
- locking to stop races with disconnect
- error handling for commands that time out

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/serial/whiteheat.c b/drivers/usb/serial/whiteheat.c
index 27c5f8f..8fd976d 100644 (file)
--- a/drivers/usb/serial/whiteheat.c
+++ b/drivers/usb/serial/whiteheat.c
@@ -74,6 +74,7 @@
 #include <linux/tty_flip.h>
 #include <linux/module.h>
 #include <linux/spinlock.h>
+#include <linux/mutex.h>
 #include <asm/uaccess.h>
 #include <asm/termbits.h>
 #include <linux/usb.h>
@@ -203,7 +204,7 @@ static struct usb_serial_driver whiteheat_device = {
 
 
 struct whiteheat_command_private {
-       spinlock_t              lock;
+       struct mutex            mutex;
        __u8                    port_running;
        __u8                    command_finished;
        wait_queue_head_t       wait_command;   /* for handling sleeping while waiting for a command to finish */
@@ -232,6 +233,7 @@ struct whiteheat_private {
        struct usb_serial_port  *port;
        struct list_head        tx_urbs_free;
        struct list_head        tx_urbs_submitted;
+       struct mutex            deathwarrant;
 };
 
 
@@ -425,6 +427,7 @@ static int whiteheat_attach (struct usb_serial *serial)
                }
 
                spin_lock_init(&info->lock);
+               mutex_init(&info->deathwarrant);
                info->flags = 0;
                info->mcr = 0;
                INIT_WORK(&info->rx_work, rx_data_softint);
@@ -495,7 +498,7 @@ static int whiteheat_attach (struct usb_serial *serial)
                goto no_command_private;
        }
 
-       spin_lock_init(&command_info->lock);
+       mutex_init(&command_info->mutex);
        command_info->port_running = 0;
        init_waitqueue_head(&command_info->wait_command);
        usb_set_serial_port_data(command_port, command_info);
@@ -654,7 +657,6 @@ static void whiteheat_close(struct usb_serial_port *port, struct file * filp)
        struct urb *urb;
        struct list_head *tmp;
        struct list_head *tmp2;
-       unsigned long flags;
 
        dbg("%s - port %d", __FUNCTION__, port->number);
        
@@ -683,24 +685,32 @@ static void whiteheat_close(struct usb_serial_port *port, struct file * filp)
 
        firm_close(port);
 
+printk(KERN_ERR"Before processing rx_urbs_submitted.\n");
        /* shutdown our bulk reads and writes */
-       spin_lock_irqsave(&info->lock, flags);
+       mutex_lock(&info->deathwarrant);
+       spin_lock_irq(&info->lock);
        list_for_each_safe(tmp, tmp2, &info->rx_urbs_submitted) {
                wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
                urb = wrap->urb;
+               list_del(tmp);
+               spin_unlock_irq(&info->lock);
                usb_kill_urb(urb);
-               list_move(tmp, &info->rx_urbs_free);
+               spin_lock_irq(&info->lock);
+               list_add(tmp, &info->rx_urbs_free);
        }
        list_for_each_safe(tmp, tmp2, &info->rx_urb_q)
                list_move(tmp, &info->rx_urbs_free);
-
        list_for_each_safe(tmp, tmp2, &info->tx_urbs_submitted) {
                wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
                urb = wrap->urb;
+               list_del(tmp);
+               spin_unlock_irq(&info->lock);
                usb_kill_urb(urb);
-               list_move(tmp, &info->tx_urbs_free);
+               spin_lock_irq(&info->lock);
+               list_add(tmp, &info->tx_urbs_free);
        }
-       spin_unlock_irqrestore(&info->lock, flags);
+       spin_unlock_irq(&info->lock);
+       mutex_unlock(&info->deathwarrant);
 
        stop_command_port(port->serial);
 
@@ -872,7 +882,7 @@ static int whiteheat_ioctl (struct usb_serial_port *port, struct file * file, un
 }
 
 
-static void whiteheat_set_termios (struct usb_serial_port *port, struct ktermios *old_termios)
+static void whiteheat_set_termios(struct usb_serial_port *port, struct ktermios *old_termios)
 {
        dbg("%s -port %d", __FUNCTION__, port->number);
 
@@ -920,7 +930,7 @@ static int whiteheat_chars_in_buffer(struct usb_serial_port *port)
        spin_unlock_irqrestore(&info->lock, flags);
 
        dbg ("%s - returns %d", __FUNCTION__, chars);
-       return (chars);
+       return chars;
 }
 
 
@@ -962,7 +972,7 @@ static void whiteheat_unthrottle (struct usb_serial_port *port)
 /*****************************************************************************
  * Connect Tech's White Heat callback routines
  *****************************************************************************/
-static void command_port_write_callback (struct urb *urb)
+static void command_port_write_callback(struct urb *urb)
 {
        dbg("%s", __FUNCTION__);
 
@@ -973,43 +983,43 @@ static void command_port_write_callback (struct urb *urb)
 }
 
 
-static void command_port_read_callback (struct urb *urb)
+static void command_port_read_callback(struct urb *urb)
 {
        struct usb_serial_port *command_port = (struct usb_serial_port *)urb->context;
        struct whiteheat_command_private *command_info;
        unsigned char *data = urb->transfer_buffer;
        int result;
-       unsigned long flags;
 
        dbg("%s", __FUNCTION__);
 
+       command_info = usb_get_serial_port_data(command_port);
+       if (!command_info) {
+               dbg ("%s - command_info is NULL, exiting.", __FUNCTION__);
+               return;
+       }
        if (urb->status) {
                dbg("%s - nonzero urb status: %d", __FUNCTION__, urb->status);
+               if (urb->status != -ENOENT)
+                       command_info->command_finished = WHITEHEAT_CMD_FAILURE;
+               wake_up(&command_info->wait_command);
                return;
        }
 
        usb_serial_debug_data(debug, &command_port->dev, __FUNCTION__, urb->actual_length, data);
 
-       command_info = usb_get_serial_port_data(command_port);
-       if (!command_info) {
-               dbg ("%s - command_info is NULL, exiting.", __FUNCTION__);
-               return;
-       }
-       spin_lock_irqsave(&command_info->lock, flags);
-
        if (data[0] == WHITEHEAT_CMD_COMPLETE) {
                command_info->command_finished = WHITEHEAT_CMD_COMPLETE;
-               wake_up_interruptible(&command_info->wait_command);
+               wake_up(&command_info->wait_command);
        } else if (data[0] == WHITEHEAT_CMD_FAILURE) {
                command_info->command_finished = WHITEHEAT_CMD_FAILURE;
-               wake_up_interruptible(&command_info->wait_command);
+               wake_up(&command_info->wait_command);
        } else if (data[0] == WHITEHEAT_EVENT) {
                /* These are unsolicited reports from the firmware, hence no waiting command to wakeup */
                dbg("%s - event received", __FUNCTION__);
        } else if (data[0] == WHITEHEAT_GET_DTR_RTS) {
                memcpy(command_info->result_buffer, &data[1], urb->actual_length - 1);
                command_info->command_finished = WHITEHEAT_CMD_COMPLETE;
-               wake_up_interruptible(&command_info->wait_command);
+               wake_up(&command_info->wait_command);
        } else {
                dbg("%s - bad reply from firmware", __FUNCTION__);
        }
@@ -1017,7 +1027,6 @@ static void command_port_read_callback (struct urb *urb)
        /* Continue trying to always read */
        command_port->read_urb->dev = command_port->serial->dev;
        result = usb_submit_urb(command_port->read_urb, GFP_ATOMIC);
-       spin_unlock_irqrestore(&command_info->lock, flags);
        if (result)
                dbg("%s - failed resubmitting read urb, error %d", __FUNCTION__, result);
 }
@@ -1095,20 +1104,20 @@ static void whiteheat_write_callback(struct urb *urb)
 /*****************************************************************************
  * Connect Tech's White Heat firmware interface
  *****************************************************************************/
-static int firm_send_command (struct usb_serial_port *port, __u8 command, __u8 *data, __u8 datasize)
+static int firm_send_command(struct usb_serial_port *port, __u8 command, __u8 *data, __u8 datasize)
 {
        struct usb_serial_port *command_port;
        struct whiteheat_command_private *command_info;
        struct whiteheat_private *info;
        __u8 *transfer_buffer;
        int retval = 0;
-       unsigned long flags;
+       int t;
 
        dbg("%s - command %d", __FUNCTION__, command);
 
        command_port = port->serial->port[COMMAND_PORT];
        command_info = usb_get_serial_port_data(command_port);
-       spin_lock_irqsave(&command_info->lock, flags);
+       mutex_lock(&command_info->mutex);
        command_info->command_finished = false;
        
        transfer_buffer = (__u8 *)command_port->write_urb->transfer_buffer;
@@ -1116,18 +1125,17 @@ static int firm_send_command (struct usb_serial_port *port, __u8 command, __u8 *
        memcpy (&transfer_buffer[1], data, datasize);
        command_port->write_urb->transfer_buffer_length = datasize + 1;
        command_port->write_urb->dev = port->serial->dev;
-       retval = usb_submit_urb (command_port->write_urb, GFP_KERNEL);
+       retval = usb_submit_urb (command_port->write_urb, GFP_NOIO);
        if (retval) {
                dbg("%s - submit urb failed", __FUNCTION__);
                goto exit;
        }
-       spin_unlock_irqrestore(&command_info->lock, flags);
 
        /* wait for the command to complete */
-       wait_event_interruptible_timeout(command_info->wait_command,
+       t = wait_event_timeout(command_info->wait_command,
                (bool)command_info->command_finished, COMMAND_TIMEOUT);
-
-       spin_lock_irqsave(&command_info->lock, flags);
+       if (!t)
+               usb_kill_urb(command_port->write_urb);
 
        if (command_info->command_finished == false) {
                dbg("%s - command timed out.", __FUNCTION__);
@@ -1152,7 +1160,7 @@ static int firm_send_command (struct usb_serial_port *port, __u8 command, __u8 *
        }
 
 exit:
-       spin_unlock_irqrestore(&command_info->lock, flags);
+       mutex_unlock(&command_info->mutex);
        return retval;
 }
 
@@ -1305,12 +1313,11 @@ static int start_command_port(struct usb_serial *serial)
 {
        struct usb_serial_port *command_port;
        struct whiteheat_command_private *command_info;
-       unsigned long flags;
        int retval = 0;
        
        command_port = serial->port[COMMAND_PORT];
        command_info = usb_get_serial_port_data(command_port);
-       spin_lock_irqsave(&command_info->lock, flags);
+       mutex_lock(&command_info->mutex);
        if (!command_info->port_running) {
                /* Work around HCD bugs */
                usb_clear_halt(serial->dev, command_port->read_urb->pipe);
@@ -1325,7 +1332,7 @@ static int start_command_port(struct usb_serial *serial)
        command_info->port_running++;
 
 exit:
-       spin_unlock_irqrestore(&command_info->lock, flags);
+       mutex_unlock(&command_info->mutex);
        return retval;
 }
 
@@ -1334,15 +1341,14 @@ static void stop_command_port(struct usb_serial *serial)
 {
        struct usb_serial_port *command_port;
        struct whiteheat_command_private *command_info;
-       unsigned long flags;
 
        command_port = serial->port[COMMAND_PORT];
        command_info = usb_get_serial_port_data(command_port);
-       spin_lock_irqsave(&command_info->lock, flags);
+       mutex_lock(&command_info->mutex);
        command_info->port_running--;
        if (!command_info->port_running)
                usb_kill_urb(command_port->read_urb);
-       spin_unlock_irqrestore(&command_info->lock, flags);
+       mutex_unlock(&command_info->mutex);
 }
 
 
@@ -1363,17 +1369,23 @@ static int start_port_read(struct usb_serial_port *port)
                wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
                urb = wrap->urb;
                urb->dev = port->serial->dev;
+               spin_unlock_irqrestore(&info->lock, flags);
                retval = usb_submit_urb(urb, GFP_KERNEL);
                if (retval) {
+                       spin_lock_irqsave(&info->lock, flags);
                        list_add(tmp, &info->rx_urbs_free);
                        list_for_each_safe(tmp, tmp2, &info->rx_urbs_submitted) {
                                wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
                                urb = wrap->urb;
+                               list_del(tmp);
+                               spin_unlock_irqrestore(&info->lock, flags);
                                usb_kill_urb(urb);
-                               list_move(tmp, &info->rx_urbs_free);
+                               spin_lock_irqsave(&info->lock, flags);
+                               list_add(tmp, &info->rx_urbs_free);
                        }
                        break;
                }
+               spin_lock_irqsave(&info->lock, flags);
                list_add(tmp, &info->rx_urbs_submitted);
        }