[PATCH] USB: convert a bunch of USB semaphores to mutexes

the patch below converts a bunch of semaphores-used-as-mutex in the USB
code to mutexes

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 12 insertions, 11 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 97bdeb1c218..6dd339f4c0f 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -60,6 +60,7 @@
 #include <linux/tty_flip.h>
 #include <linux/module.h>
 #include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <asm/uaccess.h>
 #include <linux/usb.h>
 #include <linux/usb_cdc.h>
@@ -80,7 +81,7 @@ static struct usb_driver acm_driver;
 static struct tty_driver *acm_tty_driver;
 static struct acm *acm_table[ACM_TTY_MINORS];
 
-static DECLARE_MUTEX(open_sem);
+static DEFINE_MUTEX(open_mutex);
 
 #define ACM_READY(acm)  (acm && acm->dev && acm->used)
 
@@ -431,8 +432,8 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
         int rv = -EINVAL;
         int i;
         dbg("Entering acm_tty_open.\n");
-        
-        down(&open_sem);
+
+        mutex_lock(&open_mutex);
 
         acm = acm_table[tty->index];
         if (!acm || !acm->dev)
@@ -474,14 +475,14 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
 
 done:
 err_out:
-        up(&open_sem);
+        mutex_unlock(&open_mutex);
         return rv;
 
 full_bailout:
         usb_kill_urb(acm->ctrlurb);
 bail_out:
         acm->used--;
-        up(&open_sem);
+        mutex_unlock(&open_mutex);
         return -EIO;
 }
 
@@ -507,7 +508,7 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp)
         if (!acm || !acm->used)
                 return;
 
-        down(&open_sem);
+        mutex_lock(&open_mutex);
         if (!--acm->used) {
                 if (acm->dev) {
                         acm_set_control(acm, acm->ctrlout = 0);
@@ -518,7 +519,7 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp)
                 } else
                         acm_tty_unregister(acm);
         }
-        up(&open_sem);
+        mutex_unlock(&open_mutex);
 }
 
 static int acm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
@@ -1013,9 +1014,9 @@ static void acm_disconnect(struct usb_interface *intf)
                 return;
         }
 
-        down(&open_sem);
+        mutex_lock(&open_mutex);
         if (!usb_get_intfdata(intf)) {
-                up(&open_sem);
+                mutex_unlock(&open_mutex);
                 return;
         }
         acm->dev = NULL;
@@ -1045,11 +1046,11 @@ static void acm_disconnect(struct usb_interface *intf)
 
         if (!acm->used) {
                 acm_tty_unregister(acm);
-                up(&open_sem);
+                mutex_unlock(&open_mutex);
                 return;
         }
 
-        up(&open_sem);
+        mutex_unlock(&open_mutex);
 
         if (acm->tty)
                 tty_hangup(acm->tty);