[patch 1/3] Convert stats_sem in a mutex

From: matthias
Date: Mon Feb 18 2008 - 15:40:42 EST


The semaphore cp->mutex is used as mutex, convert it to the mutex API

Signed-off-by: Matthias Kaehlcke <matthias@xxxxxxxxxxxx>

Index: linux-2.6/drivers/usb/misc/auerswald.c
===================================================================
--- linux-2.6.orig/drivers/usb/misc/auerswald.c 2008-02-18 19:47:18.000000000 +0100
+++ linux-2.6/drivers/usb/misc/auerswald.c 2008-02-18 19:51:52.000000000 +0100
@@ -31,6 +31,7 @@
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/usb.h>
+#include <linux/mutex.h>

/*-------------------------------------------------------------------*/
/* Debug support */
@@ -232,7 +233,7 @@
/* USB device context */
typedef struct
{
- struct semaphore mutex; /* protection in user context */
+ struct mutex mutex; /* protection in user context */
char name[20]; /* name of the /dev/usb entry */
unsigned int dtindex; /* index in the device table */
struct usb_device * usbdev; /* USB device handle */
@@ -1376,7 +1377,7 @@
if (cp == NULL) {
return -ENODEV;
}
- if (down_interruptible (&cp->mutex)) {
+ if (mutex_lock_interruptible(&cp->mutex)) {
return -ERESTARTSYS;
}

@@ -1405,7 +1406,7 @@
cp->open_count++;
ccp->auerdev = cp;
dbg("open %s as /dev/%s", cp->dev_desc, cp->name);
- up (&cp->mutex);
+ mutex_unlock(&cp->mutex);

/* file IO stuff */
file->f_pos = 0;
@@ -1413,7 +1414,7 @@
return nonseekable_open(inode, file);

/* Error exit */
-ofail: up (&cp->mutex);
+ofail: mutex_unlock(&cp->mutex);
auerchar_delete (ccp);
return ret;
}
@@ -1440,14 +1441,14 @@
up (&ccp->mutex);
return -ENODEV;
}
- if (down_interruptible (&cp->mutex)) {
+ if (mutex_lock_interruptible(&cp->mutex)) {
up(&ccp->mutex);
return -ERESTARTSYS;
}

/* Check for removal */
if (!cp->usbdev) {
- up(&cp->mutex);
+ mutex_unlock(&cp->mutex);
up(&ccp->mutex);
return -ENODEV;
}
@@ -1550,7 +1551,7 @@
break;
}
/* release the mutexes */
- up(&cp->mutex);
+ mutex_unlock(&cp->mutex);
up(&ccp->mutex);
return ret;
}
@@ -1721,12 +1722,12 @@
up (&ccp->mutex);
return -ERESTARTSYS;
}
- if (down_interruptible (&cp->mutex)) {
+ if (mutex_lock_interruptible(&cp->mutex)) {
up (&ccp->mutex);
return -ERESTARTSYS;
}
if (!cp->usbdev) {
- up (&cp->mutex);
+ mutex_unlock(&cp->mutex);
up (&ccp->mutex);
return -EIO;
}
@@ -1750,7 +1751,7 @@

/* are there any buffers left? */
if (!bp) {
- up (&cp->mutex);
+ mutex_unlock(&cp->mutex);
up (&ccp->mutex);

/* NONBLOCK: don't wait */
@@ -1783,7 +1784,7 @@
auerbuf_releasebuf (bp);
/* Wake up all processes waiting for a buffer */
wake_up (&cp->bufferwait);
- up (&cp->mutex);
+ mutex_unlock(&cp->mutex);
up (&ccp->mutex);
return -EFAULT;
}
@@ -1803,7 +1804,7 @@
auerchar_ctrlwrite_complete, bp);
/* up we go */
ret = auerchain_submit_urb (&cp->controlchain, bp->urbp);
- up (&cp->mutex);
+ mutex_unlock(&cp->mutex);
if (ret) {
dbg ("auerchar_write: nonzero result of auerchain_submit_urb %d", ret);
auerbuf_releasebuf (bp);
@@ -1830,16 +1831,16 @@
down(&ccp->mutex);
cp = ccp->auerdev;
if (cp) {
- down(&cp->mutex);
+ mutex_lock(&cp->mutex);
/* remove an open service */
auerswald_removeservice (cp, &ccp->scontext);
/* detach from device */
if ((--cp->open_count <= 0) && (cp->usbdev == NULL)) {
/* usb device waits for removal */
- up (&cp->mutex);
+ mutex_unlock(&cp->mutex);
auerswald_delete (cp);
} else {
- up (&cp->mutex);
+ mutex_unlock(&cp->mutex);
}
cp = NULL;
ccp->auerdev = NULL;
@@ -1917,7 +1918,7 @@
}

/* Initialize device descriptor */
- init_MUTEX (&cp->mutex);
+ mutex_init(&cp->mutex);
cp->usbdev = usbdev;
auerchain_init (&cp->controlchain);
auerbuf_init (&cp->bufctl);
@@ -2042,7 +2043,7 @@
/* give back our USB minor number */
usb_deregister_dev(intf, &auerswald_class);

- down (&cp->mutex);
+ mutex_lock(&cp->mutex);
info ("device /dev/%s now disconnecting", cp->name);

/* Stop the interrupt endpoint */
@@ -2057,16 +2058,18 @@

if (cp->open_count == 0) {
/* nobody is using this device. So we can clean up now */
- up (&cp->mutex);/* up() is possible here because no other task
- can open the device (see above). I don't want
- to kfree() a locked mutex. */
+ mutex_unlock(&cp->mutex);
+ /* mutex_unlock() is possible here because no other task
+ can open the device (see above). I don't want
+ to kfree() a locked mutex. */
+
auerswald_delete (cp);
} else {
/* device is used. Remove the pointer to the
usb device (it's not valid any more). The last
release() will do the clean up */
cp->usbdev = NULL;
- up (&cp->mutex);
+ mutex_unlock(&cp->mutex);
/* Terminate waiting writers */
wake_up (&cp->bufferwait);
/* Inform all waiting readers */

--
Matthias Kaehlcke
Linux System Developer
Barcelona

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(Isaac Newton)
.''`.
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