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path: root/drivers/usb/misc/legousbtower.c
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Diffstat (limited to 'drivers/usb/misc/legousbtower.c')
-rw-r--r--drivers/usb/misc/legousbtower.c63
1 files changed, 26 insertions, 37 deletions
diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c
index 5628f678ab59..a1ed6be87471 100644
--- a/drivers/usb/misc/legousbtower.c
+++ b/drivers/usb/misc/legousbtower.c
@@ -183,7 +183,6 @@ static const struct usb_device_id tower_table[] = {
};
MODULE_DEVICE_TABLE (usb, tower_table);
-static DEFINE_MUTEX(open_disc_mutex);
#define LEGO_USB_TOWER_MINOR_BASE 160
@@ -195,6 +194,7 @@ struct lego_usb_tower {
unsigned char minor; /* the starting minor number for this device */
int open_count; /* number of times this port has been opened */
+ unsigned long disconnected:1;
char* read_buffer;
size_t read_buffer_length; /* this much came in */
@@ -294,14 +294,13 @@ static inline void lego_usb_tower_debug_data(struct device *dev,
*/
static inline void tower_delete (struct lego_usb_tower *dev)
{
- tower_abort_transfers (dev);
-
/* free data structures */
usb_free_urb(dev->interrupt_in_urb);
usb_free_urb(dev->interrupt_out_urb);
kfree (dev->read_buffer);
kfree (dev->interrupt_in_buffer);
kfree (dev->interrupt_out_buffer);
+ usb_put_dev(dev->udev);
kfree (dev);
}
@@ -336,18 +335,14 @@ static int tower_open (struct inode *inode, struct file *file)
goto exit;
}
- mutex_lock(&open_disc_mutex);
dev = usb_get_intfdata(interface);
-
if (!dev) {
- mutex_unlock(&open_disc_mutex);
retval = -ENODEV;
goto exit;
}
/* lock this device */
if (mutex_lock_interruptible(&dev->lock)) {
- mutex_unlock(&open_disc_mutex);
retval = -ERESTARTSYS;
goto exit;
}
@@ -355,12 +350,9 @@ static int tower_open (struct inode *inode, struct file *file)
/* allow opening only once */
if (dev->open_count) {
- mutex_unlock(&open_disc_mutex);
retval = -EBUSY;
goto unlock_exit;
}
- dev->open_count = 1;
- mutex_unlock(&open_disc_mutex);
/* reset the tower */
result = usb_control_msg (dev->udev,
@@ -400,13 +392,14 @@ static int tower_open (struct inode *inode, struct file *file)
dev_err(&dev->udev->dev,
"Couldn't submit interrupt_in_urb %d\n", retval);
dev->interrupt_in_running = 0;
- dev->open_count = 0;
goto unlock_exit;
}
/* save device in the file's private structure */
file->private_data = dev;
+ dev->open_count = 1;
+
unlock_exit:
mutex_unlock(&dev->lock);
@@ -427,22 +420,19 @@ static int tower_release (struct inode *inode, struct file *file)
if (dev == NULL) {
retval = -ENODEV;
- goto exit_nolock;
- }
-
- mutex_lock(&open_disc_mutex);
- if (mutex_lock_interruptible(&dev->lock)) {
- retval = -ERESTARTSYS;
goto exit;
}
+ mutex_lock(&dev->lock);
+
if (dev->open_count != 1) {
dev_dbg(&dev->udev->dev, "%s: device not opened exactly once\n",
__func__);
retval = -ENODEV;
goto unlock_exit;
}
- if (dev->udev == NULL) {
+
+ if (dev->disconnected) {
/* the device was unplugged before the file was released */
/* unlock here as tower_delete frees dev */
@@ -460,10 +450,7 @@ static int tower_release (struct inode *inode, struct file *file)
unlock_exit:
mutex_unlock(&dev->lock);
-
exit:
- mutex_unlock(&open_disc_mutex);
-exit_nolock:
return retval;
}
@@ -481,10 +468,9 @@ static void tower_abort_transfers (struct lego_usb_tower *dev)
if (dev->interrupt_in_running) {
dev->interrupt_in_running = 0;
mb();
- if (dev->udev)
- usb_kill_urb (dev->interrupt_in_urb);
+ usb_kill_urb(dev->interrupt_in_urb);
}
- if (dev->interrupt_out_busy && dev->udev)
+ if (dev->interrupt_out_busy)
usb_kill_urb(dev->interrupt_out_urb);
}
@@ -520,7 +506,7 @@ static unsigned int tower_poll (struct file *file, poll_table *wait)
dev = file->private_data;
- if (!dev->udev)
+ if (dev->disconnected)
return POLLERR | POLLHUP;
poll_wait(file, &dev->read_wait, wait);
@@ -567,7 +553,7 @@ static ssize_t tower_read (struct file *file, char __user *buffer, size_t count,
}
/* verify that the device wasn't unplugged */
- if (dev->udev == NULL) {
+ if (dev->disconnected) {
retval = -ENODEV;
pr_err("No device or device unplugged %d\n", retval);
goto unlock_exit;
@@ -653,7 +639,7 @@ static ssize_t tower_write (struct file *file, const char __user *buffer, size_t
}
/* verify that the device wasn't unplugged */
- if (dev->udev == NULL) {
+ if (dev->disconnected) {
retval = -ENODEV;
pr_err("No device or device unplugged %d\n", retval);
goto unlock_exit;
@@ -762,7 +748,7 @@ static void tower_interrupt_in_callback (struct urb *urb)
resubmit:
/* resubmit if we're still running */
- if (dev->interrupt_in_running && dev->udev) {
+ if (dev->interrupt_in_running) {
retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC);
if (retval)
dev_err(&dev->udev->dev,
@@ -825,8 +811,9 @@ static int tower_probe (struct usb_interface *interface, const struct usb_device
mutex_init(&dev->lock);
- dev->udev = udev;
+ dev->udev = usb_get_dev(udev);
dev->open_count = 0;
+ dev->disconnected = 0;
dev->read_buffer = NULL;
dev->read_buffer_length = 0;
@@ -894,8 +881,10 @@ static int tower_probe (struct usb_interface *interface, const struct usb_device
get_version_reply,
sizeof(*get_version_reply),
1000);
- if (result < 0) {
- dev_err(idev, "LEGO USB Tower get version control request failed\n");
+ if (result != sizeof(*get_version_reply)) {
+ if (result >= 0)
+ result = -EIO;
+ dev_err(idev, "get version request failed: %d\n", result);
retval = result;
goto error;
}
@@ -913,7 +902,6 @@ static int tower_probe (struct usb_interface *interface, const struct usb_device
if (retval) {
/* something prevented us from registering this driver */
dev_err(idev, "Not able to get a minor for this device.\n");
- usb_set_intfdata (interface, NULL);
goto error;
}
dev->minor = interface->minor;
@@ -945,23 +933,24 @@ static void tower_disconnect (struct usb_interface *interface)
int minor;
dev = usb_get_intfdata (interface);
- mutex_lock(&open_disc_mutex);
- usb_set_intfdata (interface, NULL);
minor = dev->minor;
- /* give back our minor */
+ /* give back our minor and prevent further open() */
usb_deregister_dev (interface, &tower_class);
+ /* stop I/O */
+ usb_poison_urb(dev->interrupt_in_urb);
+ usb_poison_urb(dev->interrupt_out_urb);
+
mutex_lock(&dev->lock);
- mutex_unlock(&open_disc_mutex);
/* if the device is not opened, then we clean up right now */
if (!dev->open_count) {
mutex_unlock(&dev->lock);
tower_delete (dev);
} else {
- dev->udev = NULL;
+ dev->disconnected = 1;
/* wake up pollers */
wake_up_interruptible_all(&dev->read_wait);
wake_up_interruptible_all(&dev->write_wait);