[PATCH] w1: Use mutexes instead of semaphores.

Use mutexes instead of semaphores.
Patch tested on x86_64 and i386 with test bus master driver.

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/w1/masters/ds2482.c

@@ -125,7 +125,7 @@ struct ds2482_w1_chan {
 
 struct ds2482_data {
 	struct i2c_client	client;
-	struct semaphore	access_lock;
+	struct mutex		access_lock;
 
 	/* 1-wire interface(s) */
 	int			w1_count;	/* 1 or 8 */
@@ -265,7 +265,7 @@ static u8 ds2482_w1_touch_bit(void *data, u8 bit)
 	struct ds2482_data    *pdev = pchan->pdev;
 	int status = -1;
 
-	down(&pdev->access_lock);
+	mutex_lock(&pdev->access_lock);
 
 	/* Select the channel */
 	ds2482_wait_1wire_idle(pdev);
@@ -277,7 +277,7 @@ static u8 ds2482_w1_touch_bit(void *data, u8 bit)
 				  bit ? 0xFF : 0))
 		status = ds2482_wait_1wire_idle(pdev);
 
-	up(&pdev->access_lock);
+	mutex_unlock(&pdev->access_lock);
 
 	return (status & DS2482_REG_STS_SBR) ? 1 : 0;
 }
@@ -297,7 +297,7 @@ static u8 ds2482_w1_triplet(void *data, u8 dbit)
 	struct ds2482_data    *pdev = pchan->pdev;
 	int status = (3 << 5);
 
-	down(&pdev->access_lock);
+	mutex_lock(&pdev->access_lock);
 
 	/* Select the channel */
 	ds2482_wait_1wire_idle(pdev);
@@ -309,7 +309,7 @@ static u8 ds2482_w1_triplet(void *data, u8 dbit)
 				  dbit ? 0xFF : 0))
 		status = ds2482_wait_1wire_idle(pdev);
 
-	up(&pdev->access_lock);
+	mutex_unlock(&pdev->access_lock);
 
 	/* Decode the status */
 	return (status >> 5);
@@ -326,7 +326,7 @@ static void ds2482_w1_write_byte(void *data, u8 byte)
 	struct ds2482_w1_chan *pchan = data;
 	struct ds2482_data    *pdev = pchan->pdev;
 
-	down(&pdev->access_lock);
+	mutex_lock(&pdev->access_lock);
 
 	/* Select the channel */
 	ds2482_wait_1wire_idle(pdev);
@@ -336,7 +336,7 @@ static void ds2482_w1_write_byte(void *data, u8 byte)
 	/* Send the write byte command */
 	ds2482_send_cmd_data(pdev, DS2482_CMD_1WIRE_WRITE_BYTE, byte);
 
-	up(&pdev->access_lock);
+	mutex_unlock(&pdev->access_lock);
 }
 
 /**
@@ -351,7 +351,7 @@ static u8 ds2482_w1_read_byte(void *data)
 	struct ds2482_data    *pdev = pchan->pdev;
 	int result;
 
-	down(&pdev->access_lock);
+	mutex_lock(&pdev->access_lock);
 
 	/* Select the channel */
 	ds2482_wait_1wire_idle(pdev);
@@ -370,7 +370,7 @@ static u8 ds2482_w1_read_byte(void *data)
 	/* Read the data byte */
 	result = i2c_smbus_read_byte(&pdev->client);
 
-	up(&pdev->access_lock);
+	mutex_unlock(&pdev->access_lock);
 
 	return result;
 }
@@ -389,7 +389,7 @@ static u8 ds2482_w1_reset_bus(void *data)
 	int err;
 	u8 retval = 1;
 
-	down(&pdev->access_lock);
+	mutex_lock(&pdev->access_lock);
 
 	/* Select the channel */
 	ds2482_wait_1wire_idle(pdev);
@@ -409,7 +409,7 @@ static u8 ds2482_w1_reset_bus(void *data)
 					     0xF0);
 	}
 
-	up(&pdev->access_lock);
+	mutex_unlock(&pdev->access_lock);
 
 	return retval;
 }
@@ -482,7 +482,7 @@ static int ds2482_detect(struct i2c_adapter *adapter, int address, int kind)
 	snprintf(new_client->name, sizeof(new_client->name), "ds2482-%d00",
 		 data->w1_count);
 
-	init_MUTEX(&data->access_lock);
+	mutex_init(&data->access_lock);
 
 	/* Tell the I2C layer a new client has arrived */
 	if ((err = i2c_attach_client(new_client)))

drivers/w1/masters/ds2490.c

@@ -169,7 +169,7 @@ static int ds_send_control(struct ds_device *, u16, u16);
 static int ds_send_control_cmd(struct ds_device *, u16, u16);
 
 static LIST_HEAD(ds_devices);
-static DECLARE_MUTEX(ds_mutex);
+static DEFINE_MUTEX(ds_mutex);
 
 static struct usb_driver ds_driver = {
 	.name =		"DS9490R",
@@ -887,9 +887,9 @@ static int ds_probe(struct usb_interface *intf,
 	if (err)
 		goto err_out_clear;
 
-	down(&ds_mutex);
+	mutex_lock(&ds_mutex);
 	list_add_tail(&dev->ds_entry, &ds_devices);
-	up(&ds_mutex);
+	mutex_unlock(&ds_mutex);
 
 	return 0;
 
@@ -909,9 +909,9 @@ static void ds_disconnect(struct usb_interface *intf)
 	if (!dev)
 		return;
 
-	down(&ds_mutex);
+	mutex_lock(&ds_mutex);
 	list_del(&dev->ds_entry);
-	up(&ds_mutex);
+	mutex_unlock(&ds_mutex);
 
 	ds_w1_fini(dev);
 

drivers/w1/slaves/w1_ds2433.c

@@ -105,11 +105,7 @@ static ssize_t w1_f23_read_bin(struct kobject *kobj, char *buf, loff_t off,
 	if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
 		return 0;
 
-	atomic_inc(&sl->refcnt);
-	if (down_interruptible(&sl->master->mutex)) {
-		count = 0;
-		goto out_dec;
-	}
+	mutex_lock(&sl->master->mutex);
 
 #ifdef CONFIG_W1_F23_CRC
 
@@ -140,9 +136,7 @@ static ssize_t w1_f23_read_bin(struct kobject *kobj, char *buf, loff_t off,
 #endif	/* CONFIG_W1_F23_CRC */
 
 out_up:
-	up(&sl->master->mutex);
-out_dec:
-	atomic_dec(&sl->refcnt);
+	mutex_unlock(&sl->master->mutex);
 
 	return count;
 }
@@ -231,11 +225,7 @@ static ssize_t w1_f23_write_bin(struct kobject *kobj, char *buf, loff_t off,
 	}
 #endif	/* CONFIG_W1_F23_CRC */
 
-	atomic_inc(&sl->refcnt);
-	if (down_interruptible(&sl->master->mutex)) {
-		count = 0;
-		goto out_dec;
-	}
+	mutex_lock(&sl->master->mutex);
 
 	/* Can only write data to one page at a time */
 	idx = 0;
@@ -253,9 +243,7 @@ static ssize_t w1_f23_write_bin(struct kobject *kobj, char *buf, loff_t off,
 	}
 
 out_up:
-	up(&sl->master->mutex);
-out_dec:
-	atomic_dec(&sl->refcnt);
+	mutex_unlock(&sl->master->mutex);
 
 	return count;
 }

drivers/w1/slaves/w1_therm.c

@@ -165,12 +165,7 @@ static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, si
 	u8 rom[9], crc, verdict;
 	int i, max_trying = 10;
 
-	atomic_inc(&sl->refcnt);
-	smp_mb__after_atomic_inc();
-	if (down_interruptible(&sl->master->mutex)) {
-		count = 0;
-		goto out_dec;
-	}
+	mutex_lock(&sl->master->mutex);
 
 	if (off > W1_SLAVE_DATA_SIZE) {
 		count = 0;
@@ -233,10 +228,7 @@ static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, si
 
 	count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom, sl->family->fid));
 out:
-	up(&dev->mutex);
-out_dec:
-	smp_mb__before_atomic_inc();
-	atomic_dec(&sl->refcnt);
+	mutex_unlock(&dev->mutex);
 
 	return count;
 }