USB: use mutex instead of semaphore in the Adutux driver
The Adutux driver uses a semaphore as mutex. Use the mutex API instead of the (binary) semaphore. Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Matthias Kaehlcke
Greg Kroah-Hartman
parent
d2066eb659
commit
8293c568b2
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@ -24,6 +24,7 @@
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/usb.h>
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#include <linux/mutex.h>
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#include <asm/uaccess.h>
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#ifdef CONFIG_USB_DEBUG
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@ -80,7 +81,7 @@ MODULE_DEVICE_TABLE(usb, device_table);
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/* Structure to hold all of our device specific stuff */
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struct adu_device {
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struct semaphore sem; /* locks this structure */
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struct mutex mtx; /* locks this structure */
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struct usb_device* udev; /* save off the usb device pointer */
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struct usb_interface* interface;
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unsigned char minor; /* the starting minor number for this device */
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@ -269,8 +270,8 @@ static int adu_open(struct inode *inode, struct file *file)
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}
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/* lock this device */
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if ((retval = down_interruptible(&dev->sem))) {
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dbg(2, "%s : sem down failed", __FUNCTION__);
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if ((retval = mutex_lock_interruptible(&dev->mtx))) {
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dbg(2, "%s : mutex lock failed", __FUNCTION__);
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goto exit_no_device;
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}
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@ -299,7 +300,7 @@ static int adu_open(struct inode *inode, struct file *file)
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if (retval)
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--dev->open_count;
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}
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up(&dev->sem);
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mutex_unlock(&dev->mtx);
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exit_no_device:
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dbg(2,"%s : leave, return value %d ", __FUNCTION__, retval);
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@ -347,7 +348,7 @@ static int adu_release(struct inode *inode, struct file *file)
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}
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/* lock our device */
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down(&dev->sem); /* not interruptible */
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mutex_lock(&dev->mtx); /* not interruptible */
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if (dev->open_count <= 0) {
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dbg(1," %s : device not opened", __FUNCTION__);
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@ -357,7 +358,7 @@ static int adu_release(struct inode *inode, struct file *file)
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if (dev->udev == NULL) {
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/* the device was unplugged before the file was released */
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up(&dev->sem);
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mutex_unlock(&dev->mtx);
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adu_delete(dev);
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dev = NULL;
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} else {
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@ -367,7 +368,7 @@ static int adu_release(struct inode *inode, struct file *file)
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exit:
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if (dev)
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up(&dev->sem);
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mutex_unlock(&dev->mtx);
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dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
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return retval;
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}
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@ -390,7 +391,7 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
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dev = file->private_data;
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dbg(2," %s : dev=%p", __FUNCTION__, dev);
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/* lock this object */
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if (down_interruptible(&dev->sem))
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if (mutex_lock_interruptible(&dev->mtx))
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return -ERESTARTSYS;
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/* verify that the device wasn't unplugged */
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@ -522,7 +523,7 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
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exit:
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/* unlock the device */
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up(&dev->sem);
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mutex_unlock(&dev->mtx);
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dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
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return retval;
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@ -543,7 +544,7 @@ static ssize_t adu_write(struct file *file, const __user char *buffer,
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dev = file->private_data;
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/* lock this object */
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retval = down_interruptible(&dev->sem);
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retval = mutex_lock_interruptible(&dev->mtx);
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if (retval)
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goto exit_nolock;
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@ -571,9 +572,9 @@ static ssize_t adu_write(struct file *file, const __user char *buffer,
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retval = -EINTR;
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goto exit;
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}
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up(&dev->sem);
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mutex_unlock(&dev->mtx);
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timeout = interruptible_sleep_on_timeout(&dev->write_wait, timeout);
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retval = down_interruptible(&dev->sem);
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retval = mutex_lock_interruptible(&dev->mtx);
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if (retval) {
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retval = bytes_written ? bytes_written : retval;
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goto exit_nolock;
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@ -638,7 +639,7 @@ static ssize_t adu_write(struct file *file, const __user char *buffer,
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exit:
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/* unlock the device */
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up(&dev->sem);
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mutex_unlock(&dev->mtx);
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exit_nolock:
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dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
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@ -698,7 +699,7 @@ static int adu_probe(struct usb_interface *interface,
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goto exit;
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}
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init_MUTEX(&dev->sem);
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mutex_init(&dev->mtx);
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spin_lock_init(&dev->buflock);
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dev->udev = udev;
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init_waitqueue_head(&dev->read_wait);
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@ -835,16 +836,16 @@ static void adu_disconnect(struct usb_interface *interface)
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usb_deregister_dev(interface, &adu_class);
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dev->minor = 0;
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down(&dev->sem); /* not interruptible */
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mutex_lock(&dev->mtx); /* not interruptible */
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/* if the device is not opened, then we clean up right now */
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dbg(2," %s : open count %d", __FUNCTION__, dev->open_count);
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if (!dev->open_count) {
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up(&dev->sem);
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mutex_unlock(&dev->mtx);
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adu_delete(dev);
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} else {
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dev->udev = NULL;
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up(&dev->sem);
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mutex_unlock(&dev->mtx);
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}
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dev_info(&interface->dev, "ADU device adutux%d now disconnected",
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