USB: mutexification of rio500

this makes the rio500 misc usb driver use mutexes and turns uninterruptible
sleep into interruptible sleep where the semantics are not affected.

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

1 files changed, 30 insertions, 24 deletions

diff --git a/drivers/usb/misc/rio500.c b/drivers/usb/misc/rio500.c
index 384fa3769805..fdf68479a166 100644
--- a/drivers/usb/misc/rio500.c
+++ b/drivers/usb/misc/rio500.c
@@ -69,7 +69,7 @@ struct rio_usb_data {
         char *obuf, *ibuf;              /* transfer buffers */
         char bulk_in_ep, bulk_out_ep;   /* Endpoint assignments */
         wait_queue_head_t wait_q;       /* for timeouts */
-        struct semaphore lock;          /* general race avoidance */
+        struct mutex lock;          /* general race avoidance */
 };
 
 static struct rio_usb_data rio_instance;
@@ -78,17 +78,17 @@ static int open_rio(struct inode *inode, struct file *file)
 {
         struct rio_usb_data *rio = &rio_instance;
 
-        down(&(rio->lock));
+        mutex_lock(&(rio->lock));
 
         if (rio->isopen || !rio->present) {
-                up(&(rio->lock));
+                mutex_unlock(&(rio->lock));
                 return -EBUSY;
         }
         rio->isopen = 1;
 
         init_waitqueue_head(&rio->wait_q);
 
-        up(&(rio->lock));
+        mutex_unlock(&(rio->lock));
 
         info("Rio opened.");
 
@@ -117,7 +117,7 @@ ioctl_rio(struct inode *inode, struct file *file, unsigned int cmd,
         int retries;
         int retval=0;
 
-        down(&(rio->lock));
+        mutex_lock(&(rio->lock));
         /* Sanity check to make sure rio is connected, powered, etc */
         if ( rio == NULL ||
              rio->present == 0 ||
@@ -257,7 +257,7 @@ ioctl_rio(struct inode *inode, struct file *file, unsigned int cmd,
 
 
 err_out:
-        up(&(rio->lock));
+        mutex_unlock(&(rio->lock));
         return retval;
 }
 
@@ -275,14 +275,17 @@ write_rio(struct file *file, const char __user *buffer,
         int result = 0;
         int maxretry;
         int errn = 0;
+        int intr;
 
-        down(&(rio->lock));
+        intr = mutex_lock_interruptible(&(rio->lock));
+        if (intr)
+                return -EINTR;
         /* Sanity check to make sure rio is connected, powered, etc */
         if ( rio == NULL ||
              rio->present == 0 ||
              rio->rio_dev == NULL )
         {
-                up(&(rio->lock));
+                mutex_unlock(&(rio->lock));
                 return -ENODEV;
         }
 
@@ -305,7 +308,7 @@ write_rio(struct file *file, const char __user *buffer,
                                 goto error;
                         }
                         if (signal_pending(current)) {
-                                up(&(rio->lock));
+                                mutex_unlock(&(rio->lock));
                                 return bytes_written ? bytes_written : -EINTR;
                         }
 
@@ -341,12 +344,12 @@ write_rio(struct file *file, const char __user *buffer,
                 buffer += copy_size;
         } while (count > 0);
 
-        up(&(rio->lock));
+        mutex_unlock(&(rio->lock));
 
         return bytes_written ? bytes_written : -EIO;
 
 error:
-        up(&(rio->lock));
+        mutex_unlock(&(rio->lock));
         return errn;
 }
 
@@ -361,14 +364,17 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos)
         int result;
         int maxretry = 10;
         char *ibuf;
+        int intr;
 
-        down(&(rio->lock));
+        intr = mutex_lock_interruptible(&(rio->lock));
+        if (intr)
+                return -EINTR;
         /* Sanity check to make sure rio is connected, powered, etc */
         if ( rio == NULL ||
              rio->present == 0 ||
              rio->rio_dev == NULL )
         {
-                up(&(rio->lock));
+                mutex_unlock(&(rio->lock));
                 return -ENODEV;
         }
 
@@ -379,11 +385,11 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos)
 
         while (count > 0) {
                 if (signal_pending(current)) {
-                        up(&(rio->lock));
+                        mutex_unlock(&(rio->lock));
                         return read_count ? read_count : -EINTR;
                 }
                 if (!rio->rio_dev) {
-                        up(&(rio->lock));
+                        mutex_unlock(&(rio->lock));
                         return -ENODEV;
                 }
                 this_read = (count >= IBUF_SIZE) ? IBUF_SIZE : count;
@@ -400,7 +406,7 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos)
                         count = this_read = partial;
                 } else if (result == -ETIMEDOUT || result == 15) {      /* FIXME: 15 ??? */
                         if (!maxretry--) {
-                                up(&(rio->lock));
+                                mutex_unlock(&(rio->lock));
                                 err("read_rio: maxretry timeout");
                                 return -ETIME;
                         }
@@ -409,18 +415,18 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos)
                         finish_wait(&rio->wait_q, &wait);
                         continue;
                 } else if (result != -EREMOTEIO) {
-                        up(&(rio->lock));
+                        mutex_unlock(&(rio->lock));
                         err("Read Whoops - result:%u partial:%u this_read:%u",
                              result, partial, this_read);
                         return -EIO;
                 } else {
-                        up(&(rio->lock));
+                        mutex_unlock(&(rio->lock));
                         return (0);
                 }
 
                 if (this_read) {
                         if (copy_to_user(buffer, ibuf, this_read)) {
-                                up(&(rio->lock));
+                                mutex_unlock(&(rio->lock));
                                 return -EFAULT;
                         }
                         count -= this_read;
@@ -428,7 +434,7 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos)
                         buffer += this_read;
                 }
         }
-        up(&(rio->lock));
+        mutex_unlock(&(rio->lock));
         return read_count;
 }
 
@@ -480,7 +486,7 @@ static int probe_rio(struct usb_interface *intf,
         }
         dbg("probe_rio: ibuf address:%p", rio->ibuf);
 
-        init_MUTEX(&(rio->lock));
+        mutex_init(&(rio->lock));
 
         usb_set_intfdata (intf, rio);
         rio->present = 1;
@@ -496,12 +502,12 @@ static void disconnect_rio(struct usb_interface *intf)
         if (rio) {
                 usb_deregister_dev(intf, &usb_rio_class);
 
-                down(&(rio->lock));
+                mutex_lock(&(rio->lock));
                 if (rio->isopen) {
                         rio->isopen = 0;
                         /* better let it finish - the release will do whats needed */
                         rio->rio_dev = NULL;
-                        up(&(rio->lock));
+                        mutex_unlock(&(rio->lock));
                         return;
                 }
                 kfree(rio->ibuf);
@@ -510,7 +516,7 @@ static void disconnect_rio(struct usb_interface *intf)
                 info("USB Rio disconnected.");
 
                 rio->present = 0;
-                up(&(rio->lock));
+                mutex_unlock(&(rio->lock));
         }
 }