[PATCH] USB serial: Converts port semaphore to mutexes.

The usbserial's port semaphore used to synchronize serial_open()
and serial_close() are strict mutexes, convert them to the mutex
implementation.

Signed-off-by: Luiz Capitulino <lcapitulino@mandriva.com.br>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 097f4e8..071f86a 100644 (file)
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -27,10 +27,10 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/spinlock.h>
+#include <linux/mutex.h>
 #include <linux/list.h>
 #include <linux/smp_lock.h>
 #include <asm/uaccess.h>
-#include <asm/semaphore.h>
 #include <linux/usb.h>
 #include "usb-serial.h"
 #include "pl2303.h"
@@ -192,7 +192,7 @@ static int serial_open (struct tty_struct *tty, struct file * filp)
        if (!port)
                return -ENODEV;
 
-       if (down_interruptible(&port->sem))
+       if (mutex_lock_interruptible(&port->mutex))
                return -ERESTARTSYS;
         
        ++port->open_count;
@@ -219,7 +219,7 @@ static int serial_open (struct tty_struct *tty, struct file * filp)
                        goto bailout_module_put;
        }
 
-       up(&port->sem);
+       mutex_unlock(&port->mutex);
        return 0;
 
 bailout_module_put:
@@ -227,7 +227,7 @@ bailout_module_put:
 bailout_kref_put:
        kref_put(&serial->kref, destroy_serial);
        port->open_count = 0;
-       up(&port->sem);
+       mutex_unlock(&port->mutex);
        return retval;
 }
 
@@ -240,10 +240,10 @@ static void serial_close(struct tty_struct *tty, struct file * filp)
 
        dbg("%s - port %d", __FUNCTION__, port->number);
 
-       down(&port->sem);
+       mutex_lock(&port->mutex);
 
        if (port->open_count == 0) {
-               up(&port->sem);
+               mutex_unlock(&port->mutex);
                return;
        }
 
@@ -262,7 +262,7 @@ static void serial_close(struct tty_struct *tty, struct file * filp)
                module_put(port->serial->type->driver.owner);
        }
 
-       up(&port->sem);
+       mutex_unlock(&port->mutex);
        kref_put(&port->serial->kref, destroy_serial);
 }
 
@@ -783,7 +783,7 @@ int usb_serial_probe(struct usb_interface *interface,
                port->number = i + serial->minor;
                port->serial = serial;
                spin_lock_init(&port->lock);
-               sema_init(&port->sem, 1);
+               mutex_init(&port->mutex);
                INIT_WORK(&port->work, usb_serial_port_softint, port);
                serial->port[i] = port;
        }

diff --git a/drivers/usb/serial/usb-serial.h b/drivers/usb/serial/usb-serial.h
index d7d27c3..dc89d87 100644 (file)
--- a/drivers/usb/serial/usb-serial.h
+++ b/drivers/usb/serial/usb-serial.h
@@ -16,7 +16,7 @@
 
 #include <linux/config.h>
 #include <linux/kref.h>
-#include <asm/semaphore.h>
+#include <linux/mutex.h>
 
 #define SERIAL_TTY_MAJOR       188     /* Nice legal number now */
 #define SERIAL_TTY_MINORS      255     /* loads of devices :) */
@@ -31,7 +31,7 @@
  * @serial: pointer back to the struct usb_serial owner of this port.
  * @tty: pointer to the corresponding tty for this port.
  * @lock: spinlock to grab when updating portions of this structure.
- * @sem: semaphore used to synchronize serial_open() and serial_close()
+ * @mutex: mutex used to synchronize serial_open() and serial_close()
  *     access for this port.
  * @number: the number of the port (the minor number).
  * @interrupt_in_buffer: pointer to the interrupt in buffer for this port.
@@ -63,7 +63,7 @@ struct usb_serial_port {
        struct usb_serial *     serial;
        struct tty_struct *     tty;
        spinlock_t              lock;
-       struct semaphore        sem;
+       struct mutex            mutex;
        unsigned char           number;
 
        unsigned char *         interrupt_in_buffer;