17 files changed, 57 insertions, 95 deletions

diff --git a/drivers/power/ds2780_battery.c b/drivers/power/ds2780_battery.c
index de31cae1ba53..74fad941c56c 100644
--- a/drivers/power/ds2780_battery.c
+++ b/drivers/power/ds2780_battery.c
@@ -39,7 +39,6 @@ struct ds2780_device_info {
         struct device *dev;
         struct power_supply bat;
         struct device *w1_dev;
-        struct task_struct *mutex_holder;
 };
 
 enum current_types {
@@ -64,10 +63,7 @@ static inline struct power_supply *to_power_supply(struct device *dev)
 static inline int ds2780_battery_io(struct ds2780_device_info *dev_info,
         char *buf, int addr, size_t count, int io)
 {
-        if (dev_info->mutex_holder == current)
-                return w1_ds2780_io_nolock(dev_info->w1_dev, buf, addr, count, io);
-        else
-                return w1_ds2780_io(dev_info->w1_dev, buf, addr, count, io);
+        return w1_ds2780_io(dev_info->w1_dev, buf, addr, count, io);
 }
 
 static inline int ds2780_read8(struct ds2780_device_info *dev_info, u8 *val,
@@ -779,7 +775,6 @@ static int __devinit ds2780_battery_probe(struct platform_device *pdev)
         dev_info->bat.properties        = ds2780_battery_props;
         dev_info->bat.num_properties    = ARRAY_SIZE(ds2780_battery_props);
         dev_info->bat.get_property      = ds2780_battery_get_property;
-        dev_info->mutex_holder          = current;
 
         ret = power_supply_register(&pdev->dev, &dev_info->bat);
         if (ret) {
@@ -809,8 +804,6 @@ static int __devinit ds2780_battery_probe(struct platform_device *pdev)
                 goto fail_remove_bin_file;
         }
 
-        dev_info->mutex_holder = NULL;
-
         return 0;
 
 fail_remove_bin_file:
@@ -830,8 +823,6 @@ static int __devexit ds2780_battery_remove(struct platform_device *pdev)
 {
         struct ds2780_device_info *dev_info = platform_get_drvdata(pdev);
 
-        dev_info->mutex_holder = current;
-
         /* remove attributes */
         sysfs_remove_group(&dev_info->bat.dev->kobj, &ds2780_attr_group);
 
diff --git a/drivers/power/ds2781_battery.c b/drivers/power/ds2781_battery.c
index 975684a40f15..5f92a4bb33f9 100644
--- a/drivers/power/ds2781_battery.c
+++ b/drivers/power/ds2781_battery.c
@@ -37,7 +37,6 @@ struct ds2781_device_info {
         struct device *dev;
         struct power_supply bat;
         struct device *w1_dev;
-        struct task_struct *mutex_holder;
 };
 
 enum current_types {
@@ -62,11 +61,7 @@ static inline struct power_supply *to_power_supply(struct device *dev)
 static inline int ds2781_battery_io(struct ds2781_device_info *dev_info,
         char *buf, int addr, size_t count, int io)
 {
-        if (dev_info->mutex_holder == current)
-                return w1_ds2781_io_nolock(dev_info->w1_dev, buf, addr,
-                                count, io);
-        else
-                return w1_ds2781_io(dev_info->w1_dev, buf, addr, count, io);
+        return w1_ds2781_io(dev_info->w1_dev, buf, addr, count, io);
 }
 
 int w1_ds2781_read(struct ds2781_device_info *dev_info, char *buf,
@@ -775,7 +770,6 @@ static int __devinit ds2781_battery_probe(struct platform_device *pdev)
         dev_info->bat.properties        = ds2781_battery_props;
         dev_info->bat.num_properties    = ARRAY_SIZE(ds2781_battery_props);
         dev_info->bat.get_property      = ds2781_battery_get_property;
-        dev_info->mutex_holder          = current;
 
         ret = power_supply_register(&pdev->dev, &dev_info->bat);
         if (ret) {
@@ -805,8 +799,6 @@ static int __devinit ds2781_battery_probe(struct platform_device *pdev)
                 goto fail_remove_bin_file;
         }
 
-        dev_info->mutex_holder = NULL;
-
         return 0;
 
 fail_remove_bin_file:
@@ -826,8 +818,6 @@ static int __devexit ds2781_battery_remove(struct platform_device *pdev)
 {
         struct ds2781_device_info *dev_info = platform_get_drvdata(pdev);
 
-        dev_info->mutex_holder = current;
-
         /* remove attributes */
         sysfs_remove_group(&dev_info->bat.dev->kobj, &ds2781_attr_group);
 
diff --git a/drivers/w1/masters/ds1wm.c b/drivers/w1/masters/ds1wm.c
index a0c8965c1a79..530a2d309063 100644
--- a/drivers/w1/masters/ds1wm.c
+++ b/drivers/w1/masters/ds1wm.c
@@ -334,7 +334,9 @@ static void ds1wm_search(void *data, struct w1_master *master_dev,
                         return;
                 }
 
+                mutex_lock(&master_dev->bus_mutex);
                 if (ds1wm_reset(ds1wm_data)) {
+                        mutex_unlock(&master_dev->bus_mutex);
                         dev_dbg(&ds1wm_data->pdev->dev,
                                 "pass: %d reset error (or no slaves)\n", pass);
                         break;
@@ -387,6 +389,7 @@ static void ds1wm_search(void *data, struct w1_master *master_dev,
 
                 }
                 if (ds1wm_data->read_error) {
+                        mutex_unlock(&master_dev->bus_mutex);
                         dev_err(&ds1wm_data->pdev->dev,
                                 "pass: %d read error, retrying\n", pass);
                         break;
@@ -400,6 +403,7 @@ static void ds1wm_search(void *data, struct w1_master *master_dev,
                 dev_dbg(&ds1wm_data->pdev->dev,
                         "pass: %d resetting bus\n", pass);
                 ds1wm_reset(ds1wm_data);
+                mutex_unlock(&master_dev->bus_mutex);
                 if ((r_prime & ((u64)1 << 63)) && (d & ((u64)1 << 63))) {
                         dev_err(&ds1wm_data->pdev->dev,
                                 "pass: %d bus error, retrying\n", pass);
diff --git a/drivers/w1/slaves/w1_bq27000.c b/drivers/w1/slaves/w1_bq27000.c
index 52ad812fa1e7..773dca5beafe 100644
--- a/drivers/w1/slaves/w1_bq27000.c
+++ b/drivers/w1/slaves/w1_bq27000.c
@@ -31,10 +31,10 @@ static int w1_bq27000_read(struct device *dev, unsigned int reg)
         u8 val;
         struct w1_slave *sl = container_of(dev->parent, struct w1_slave, dev);
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
         w1_write_8(sl->master, HDQ_CMD_READ | reg);
         val = w1_read_8(sl->master);
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
 
         return val;
 }
diff --git a/drivers/w1/slaves/w1_ds2408.c b/drivers/w1/slaves/w1_ds2408.c
index 8e813eed0f0a..441ad3a3b586 100644
--- a/drivers/w1/slaves/w1_ds2408.c
+++ b/drivers/w1/slaves/w1_ds2408.c
@@ -52,11 +52,11 @@ static int _read_reg(struct w1_slave *sl, u8 address, unsigned char* buf)
         if (!buf)
                 return -EINVAL;
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
         dev_dbg(&sl->dev, "mutex locked");
 
         if (w1_reset_select_slave(sl)) {
-                mutex_unlock(&sl->master->mutex);
+                mutex_unlock(&sl->master->bus_mutex);
                 return -EIO;
         }
 
@@ -66,7 +66,7 @@ static int _read_reg(struct w1_slave *sl, u8 address, unsigned char* buf)
         w1_write_block(sl->master, wrbuf, 3);
         *buf = w1_read_8(sl->master);
 
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
         dev_dbg(&sl->dev, "mutex unlocked");
         return 1;
 }
@@ -165,7 +165,7 @@ static ssize_t w1_f29_write_output(
                 return -EFAULT;
 
         dev_dbg(&sl->dev, "locking mutex for write_output");
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
         dev_dbg(&sl->dev, "mutex locked");
 
         if (w1_reset_select_slave(sl))
@@ -200,14 +200,14 @@ static ssize_t w1_f29_write_output(
                 /* read the result of the READ_PIO_REGS command */
                 if (w1_read_8(sl->master) == *buf) {
                         /* success! */
-                        mutex_unlock(&sl->master->mutex);
+                        mutex_unlock(&sl->master->bus_mutex);
                         dev_dbg(&sl->dev,
                                 "mutex unlocked, retries:%d", retries);
                         return 1;
                 }
         }
 error:
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
         dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
 
         return -EIO;
@@ -228,7 +228,7 @@ static ssize_t w1_f29_write_activity(
         if (count != 1 || off != 0)
                 return -EFAULT;
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
 
         if (w1_reset_select_slave(sl))
                 goto error;
@@ -236,7 +236,7 @@ static ssize_t w1_f29_write_activity(
         while (retries--) {
                 w1_write_8(sl->master, W1_F29_FUNC_RESET_ACTIVITY_LATCHES);
                 if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE) {
-                        mutex_unlock(&sl->master->mutex);
+                        mutex_unlock(&sl->master->bus_mutex);
                         return 1;
                 }
                 if (w1_reset_resume_command(sl->master))
@@ -244,7 +244,7 @@ static ssize_t w1_f29_write_activity(
         }
 
 error:
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
         return -EIO;
 }
 
@@ -263,7 +263,7 @@ static ssize_t w1_f29_write_status_control(
         if (count != 1 || off != 0)
                 return -EFAULT;
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
 
         if (w1_reset_select_slave(sl))
                 goto error;
@@ -285,12 +285,12 @@ static ssize_t w1_f29_write_status_control(
                 w1_write_block(sl->master, w1_buf, 3);
                 if (w1_read_8(sl->master) == *buf) {
                         /* success! */
-                        mutex_unlock(&sl->master->mutex);
+                        mutex_unlock(&sl->master->bus_mutex);
                         return 1;
                 }
         }
 error:
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
 
         return -EIO;
 }
diff --git a/drivers/w1/slaves/w1_ds2423.c b/drivers/w1/slaves/w1_ds2423.c
index 7a7dbe5026f1..40a10b5ed120 100644
--- a/drivers/w1/slaves/w1_ds2423.c
+++ b/drivers/w1/slaves/w1_ds2423.c
@@ -66,7 +66,7 @@ static ssize_t w1_counter_read(struct device *device,
         wrbuf[0]        = 0xA5;
         wrbuf[1]        = rom_addr & 0xFF;
         wrbuf[2]        = rom_addr >> 8;
-        mutex_lock(&dev->mutex);
+        mutex_lock(&dev->bus_mutex);
         if (!w1_reset_select_slave(sl)) {
                 w1_write_block(dev, wrbuf, 3);
                 read_byte_count = 0;
@@ -124,7 +124,7 @@ static ssize_t w1_counter_read(struct device *device,
         } else {
                 c -= snprintf(out_buf + PAGE_SIZE - c, c, "Connection error");
         }
-        mutex_unlock(&dev->mutex);
+        mutex_unlock(&dev->bus_mutex);
         return PAGE_SIZE - c;
 }
 
diff --git a/drivers/w1/slaves/w1_ds2431.c b/drivers/w1/slaves/w1_ds2431.c
index 84e2410aec1d..984b30331a45 100644
--- a/drivers/w1/slaves/w1_ds2431.c
+++ b/drivers/w1/slaves/w1_ds2431.c
@@ -107,7 +107,7 @@ static ssize_t w1_f2d_read_bin(struct file *filp, struct kobject *kobj,
         if (count == 0)
                 return 0;
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
 
         /* read directly from the EEPROM in chunks of W1_F2D_READ_MAXLEN */
         while (todo > 0) {
@@ -126,7 +126,7 @@ static ssize_t w1_f2d_read_bin(struct file *filp, struct kobject *kobj,
                 off += W1_F2D_READ_MAXLEN;
         }
 
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
 
         return count;
 }
@@ -214,7 +214,7 @@ static ssize_t w1_f2d_write_bin(struct file *filp, struct kobject *kobj,
         if (count == 0)
                 return 0;
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
 
         /* Can only write data in blocks of the size of the scratchpad */
         addr = off;
@@ -259,7 +259,7 @@ static ssize_t w1_f2d_write_bin(struct file *filp, struct kobject *kobj,
         }
 
 out_up:
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
 
         return count;
 }
diff --git a/drivers/w1/slaves/w1_ds2433.c b/drivers/w1/slaves/w1_ds2433.c
index 0f7b8f9c509a..85f2cdb27fa2 100644
--- a/drivers/w1/slaves/w1_ds2433.c
+++ b/drivers/w1/slaves/w1_ds2433.c
@@ -107,7 +107,7 @@ static ssize_t w1_f23_read_bin(struct file *filp, struct kobject *kobj,
         if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
                 return 0;
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
 
 #ifdef CONFIG_W1_SLAVE_DS2433_CRC
 
@@ -138,7 +138,7 @@ static ssize_t w1_f23_read_bin(struct file *filp, struct kobject *kobj,
 #endif  /* CONFIG_W1_SLAVE_DS2433_CRC */
 
 out_up:
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
 
         return count;
 }
@@ -233,7 +233,7 @@ static ssize_t w1_f23_write_bin(struct file *filp, struct kobject *kobj,
         }
 #endif  /* CONFIG_W1_SLAVE_DS2433_CRC */
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
 
         /* Can only write data to one page at a time */
         idx = 0;
@@ -251,7 +251,7 @@ static ssize_t w1_f23_write_bin(struct file *filp, struct kobject *kobj,
         }
 
 out_up:
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
 
         return count;
 }
diff --git a/drivers/w1/slaves/w1_ds2760.c b/drivers/w1/slaves/w1_ds2760.c
index 5754c9a4f58b..aa7bd5fa2fa8 100644
--- a/drivers/w1/slaves/w1_ds2760.c
+++ b/drivers/w1/slaves/w1_ds2760.c
@@ -31,7 +31,7 @@ static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
         if (!dev)
                 return 0;
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
 
         if (addr > DS2760_DATA_SIZE || addr < 0) {
                 count = 0;
@@ -54,7 +54,7 @@ static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
         }
 
 out:
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
 
         return count;
 }
@@ -76,14 +76,14 @@ static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
         if (!dev)
                 return -EINVAL;
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
 
         if (w1_reset_select_slave(sl) == 0) {
                 w1_write_8(sl->master, cmd);
                 w1_write_8(sl->master, addr);
         }
 
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
         return 0;
 }
 
diff --git a/drivers/w1/slaves/w1_ds2780.c b/drivers/w1/slaves/w1_ds2780.c
index 39f78c0b143c..7b09307de0ef 100644
--- a/drivers/w1/slaves/w1_ds2780.c
+++ b/drivers/w1/slaves/w1_ds2780.c
@@ -60,30 +60,16 @@ int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
         if (!dev)
                 return -ENODEV;
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
 
         ret = w1_ds2780_do_io(dev, buf, addr, count, io);
 
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
 
         return ret;
 }
 EXPORT_SYMBOL(w1_ds2780_io);
 
-int w1_ds2780_io_nolock(struct device *dev, char *buf, int addr, size_t count,
-                        int io)
-{
-        int ret;
-
-        if (!dev)
-                return -ENODEV;
-
-        ret = w1_ds2780_do_io(dev, buf, addr, count, io);
-
-        return ret;
-}
-EXPORT_SYMBOL(w1_ds2780_io_nolock);
-
 int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
 {
         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
@@ -91,14 +77,14 @@ int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
         if (!dev)
                 return -EINVAL;
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
 
         if (w1_reset_select_slave(sl) == 0) {
                 w1_write_8(sl->master, cmd);
                 w1_write_8(sl->master, addr);
         }
 
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
         return 0;
 }
 EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);
diff --git a/drivers/w1/slaves/w1_ds2780.h b/drivers/w1/slaves/w1_ds2780.h
index 737379365021..a1fba79eb1b5 100644
--- a/drivers/w1/slaves/w1_ds2780.h
+++ b/drivers/w1/slaves/w1_ds2780.h
@@ -124,8 +124,6 @@
 
 extern int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
                         int io);
-extern int w1_ds2780_io_nolock(struct device *dev, char *buf, int addr,
-                        size_t count, int io);
 extern int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd);
 
 #endif /* !_W1_DS2780_H */
diff --git a/drivers/w1/slaves/w1_ds2781.c b/drivers/w1/slaves/w1_ds2781.c
index 0d0c7985293f..877daf74159c 100644
--- a/drivers/w1/slaves/w1_ds2781.c
+++ b/drivers/w1/slaves/w1_ds2781.c
@@ -58,30 +58,16 @@ int w1_ds2781_io(struct device *dev, char *buf, int addr, size_t count,
         if (!dev)
                 return -ENODEV;
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
 
         ret = w1_ds2781_do_io(dev, buf, addr, count, io);
 
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
 
         return ret;
 }
 EXPORT_SYMBOL(w1_ds2781_io);
 
-int w1_ds2781_io_nolock(struct device *dev, char *buf, int addr, size_t count,
-                        int io)
-{
-        int ret;
-
-        if (!dev)
-                return -ENODEV;
-
-        ret = w1_ds2781_do_io(dev, buf, addr, count, io);
-
-        return ret;
-}
-EXPORT_SYMBOL(w1_ds2781_io_nolock);
-
 int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd)
 {
         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
@@ -89,14 +75,14 @@ int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd)
         if (!dev)
                 return -EINVAL;
 
-        mutex_lock(&sl->master->mutex);
+        mutex_lock(&sl->master->bus_mutex);
 
         if (w1_reset_select_slave(sl) == 0) {
                 w1_write_8(sl->master, cmd);
                 w1_write_8(sl->master, addr);
         }
 
-        mutex_unlock(&sl->master->mutex);
+        mutex_unlock(&sl->master->bus_mutex);
         return 0;
 }
 EXPORT_SYMBOL(w1_ds2781_eeprom_cmd);
diff --git a/drivers/w1/slaves/w1_ds2781.h b/drivers/w1/slaves/w1_ds2781.h
index 82bc66497b43..557dfb0b4f64 100644
--- a/drivers/w1/slaves/w1_ds2781.h
+++ b/drivers/w1/slaves/w1_ds2781.h
@@ -129,8 +129,6 @@
 
 extern int w1_ds2781_io(struct device *dev, char *buf, int addr, size_t count,
                         int io);
-extern int w1_ds2781_io_nolock(struct device *dev, char *buf, int addr,
-                        size_t count, int io);
 extern int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd);
 
 #endif /* !_W1_DS2781_H */
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index ff29ae747ee8..d90062b211f8 100644
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -179,7 +179,7 @@ static ssize_t w1_therm_read(struct device *device,
         int i, max_trying = 10;
         ssize_t c = PAGE_SIZE;
 
-        i = mutex_lock_interruptible(&dev->mutex);
+        i = mutex_lock_interruptible(&dev->bus_mutex);
         if (i != 0)
                 return i;
 
@@ -207,19 +207,19 @@ static ssize_t w1_therm_read(struct device *device,
                         w1_write_8(dev, W1_CONVERT_TEMP);
 
                         if (external_power) {
-                                mutex_unlock(&dev->mutex);
+                                mutex_unlock(&dev->bus_mutex);
 
                                 sleep_rem = msleep_interruptible(tm);
                                 if (sleep_rem != 0)
                                         return -EINTR;
 
-                                i = mutex_lock_interruptible(&dev->mutex);
+                                i = mutex_lock_interruptible(&dev->bus_mutex);
                                 if (i != 0)
                                         return i;
                         } else if (!w1_strong_pullup) {
                                 sleep_rem = msleep_interruptible(tm);
                                 if (sleep_rem != 0) {
-                                        mutex_unlock(&dev->mutex);
+                                        mutex_unlock(&dev->bus_mutex);
                                         return -EINTR;
                                 }
                         }
@@ -258,7 +258,7 @@ static ssize_t w1_therm_read(struct device *device,
 
         c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
                 w1_convert_temp(rom, sl->family->fid));
-        mutex_unlock(&dev->mutex);
+        mutex_unlock(&dev->bus_mutex);
 
         return PAGE_SIZE - c;
 }
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index bfb898641029..1a574370d2cd 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -885,16 +885,21 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
                  *
                  * Return 0 - device(s) present, 1 - no devices present.
                  */
+                mutex_lock(&dev->bus_mutex);
                 if (w1_reset_bus(dev)) {
+                        mutex_unlock(&dev->bus_mutex);
                         dev_dbg(&dev->dev, "No devices present on the wire.\n");
                         break;
                 }
 
                 /* Do fast search on single slave bus */
                 if (dev->max_slave_count == 1) {
+                        int rv;
                         w1_write_8(dev, W1_READ_ROM);
+                        rv = w1_read_block(dev, (u8 *)&rn, 8);
+                        mutex_unlock(&dev->bus_mutex);
 
-                        if (w1_read_block(dev, (u8 *)&rn, 8) == 8 && rn)
+                        if (rv == 8 && rn)
                                 cb(dev, rn);
 
                         break;
@@ -927,10 +932,12 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
                         rn |= (tmp64 << i);
 
                         if (kthread_should_stop()) {
+                                mutex_unlock(&dev->bus_mutex);
                                 dev_dbg(&dev->dev, "Abort w1_search\n");
                                 return;
                         }
                 }
+                mutex_unlock(&dev->bus_mutex);
 
                 if ( (triplet_ret & 0x03) != 0x03 ) {
                         if ( (desc_bit == last_zero) || (last_zero < 0))
diff --git a/drivers/w1/w1.h b/drivers/w1/w1.h
index 4d012ca3f32c..45908e56c2f8 100644
--- a/drivers/w1/w1.h
+++ b/drivers/w1/w1.h
@@ -180,6 +180,7 @@ struct w1_master
 
         struct task_struct      *thread;
         struct mutex            mutex;
+        struct mutex            bus_mutex;
 
         struct device_driver    *driver;
         struct device           dev;
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
index 68288355727a..531434180afd 100644
--- a/drivers/w1/w1_int.c
+++ b/drivers/w1/w1_int.c
@@ -76,6 +76,7 @@ static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
 
         INIT_LIST_HEAD(&dev->slist);
         mutex_init(&dev->mutex);
+        mutex_init(&dev->bus_mutex);
 
         memcpy(&dev->dev, device, sizeof(struct device));
         dev_set_name(&dev->dev, "w1_bus_master%u", dev->id);