aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/w1
diff options
context:
space:
mode:
authorNeilBrown <neilb@suse.de>2012-05-18 01:59:52 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-06-13 19:38:40 -0400
commitb02f8bede217a4b145ecc16d3940c78d83941147 (patch)
treecbd02191cc2698c460b9abedea44de13855510c6 /drivers/w1
parentb7e938d06d0de43bdbee8844a8736c81480c1031 (diff)
W1: split master mutex to avoid deadlocks.
The 'mutex' in struct w1_master is use for two very different purposes. Firstly it protects various data structures such as the list of all slaves. Secondly it protects the w1 buss against concurrent accesses. This can lead to deadlocks when the ->probe code called while adding a slave needs to talk on the bus, as is the case for power_supply devices. ds2780 and ds2781 drivers contain a work around to track which process hold the lock simply to avoid this deadlock. bq27000 doesn't have that work around and so deadlocks. There are other possible deadlocks involving sysfs. When removing a device the sysfs s_active lock is held, so the lock that protects the slave list must take precedence over s_active. However when access power_supply attributes via sysfs, the s_active lock must take precedence over the lock that protects accesses to the bus. So to avoid deadlocks between w1 slaves and sysfs, these must be two separate locks. Making them separate means that the work around in ds2780 and ds2781 can be removed. So this patch: - adds a new mutex: "bus_mutex" which serialises access to the bus. - takes in mutex in w1_search and ds1wm_search while they access the bus for searching. The mutex is dropped before calling the callback which adds the slave. - changes all slaves to use bus_mutex instead of mutex to protect access to the bus - removes w1_ds2790_io_nolock and w1_ds2781_io_nolock, and the related code from drivers/power/ds278[01]_battery.c which calls them. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/w1')
-rw-r--r--drivers/w1/masters/ds1wm.c4
-rw-r--r--drivers/w1/slaves/w1_bq27000.c4
-rw-r--r--drivers/w1/slaves/w1_ds2408.c24
-rw-r--r--drivers/w1/slaves/w1_ds2423.c4
-rw-r--r--drivers/w1/slaves/w1_ds2431.c8
-rw-r--r--drivers/w1/slaves/w1_ds2433.c8
-rw-r--r--drivers/w1/slaves/w1_ds2760.c8
-rw-r--r--drivers/w1/slaves/w1_ds2780.c22
-rw-r--r--drivers/w1/slaves/w1_ds2780.h2
-rw-r--r--drivers/w1/slaves/w1_ds2781.c22
-rw-r--r--drivers/w1/slaves/w1_ds2781.h2
-rw-r--r--drivers/w1/slaves/w1_therm.c10
-rw-r--r--drivers/w1/w1.c9
-rw-r--r--drivers/w1/w1.h1
-rw-r--r--drivers/w1/w1_int.c1
15 files changed, 55 insertions, 74 deletions
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,
334 return; 334 return;
335 } 335 }
336 336
337 mutex_lock(&master_dev->bus_mutex);
337 if (ds1wm_reset(ds1wm_data)) { 338 if (ds1wm_reset(ds1wm_data)) {
339 mutex_unlock(&master_dev->bus_mutex);
338 dev_dbg(&ds1wm_data->pdev->dev, 340 dev_dbg(&ds1wm_data->pdev->dev,
339 "pass: %d reset error (or no slaves)\n", pass); 341 "pass: %d reset error (or no slaves)\n", pass);
340 break; 342 break;
@@ -387,6 +389,7 @@ static void ds1wm_search(void *data, struct w1_master *master_dev,
387 389
388 } 390 }
389 if (ds1wm_data->read_error) { 391 if (ds1wm_data->read_error) {
392 mutex_unlock(&master_dev->bus_mutex);
390 dev_err(&ds1wm_data->pdev->dev, 393 dev_err(&ds1wm_data->pdev->dev,
391 "pass: %d read error, retrying\n", pass); 394 "pass: %d read error, retrying\n", pass);
392 break; 395 break;
@@ -400,6 +403,7 @@ static void ds1wm_search(void *data, struct w1_master *master_dev,
400 dev_dbg(&ds1wm_data->pdev->dev, 403 dev_dbg(&ds1wm_data->pdev->dev,
401 "pass: %d resetting bus\n", pass); 404 "pass: %d resetting bus\n", pass);
402 ds1wm_reset(ds1wm_data); 405 ds1wm_reset(ds1wm_data);
406 mutex_unlock(&master_dev->bus_mutex);
403 if ((r_prime & ((u64)1 << 63)) && (d & ((u64)1 << 63))) { 407 if ((r_prime & ((u64)1 << 63)) && (d & ((u64)1 << 63))) {
404 dev_err(&ds1wm_data->pdev->dev, 408 dev_err(&ds1wm_data->pdev->dev,
405 "pass: %d bus error, retrying\n", pass); 409 "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)
31 u8 val; 31 u8 val;
32 struct w1_slave *sl = container_of(dev->parent, struct w1_slave, dev); 32 struct w1_slave *sl = container_of(dev->parent, struct w1_slave, dev);
33 33
34 mutex_lock(&sl->master->mutex); 34 mutex_lock(&sl->master->bus_mutex);
35 w1_write_8(sl->master, HDQ_CMD_READ | reg); 35 w1_write_8(sl->master, HDQ_CMD_READ | reg);
36 val = w1_read_8(sl->master); 36 val = w1_read_8(sl->master);
37 mutex_unlock(&sl->master->mutex); 37 mutex_unlock(&sl->master->bus_mutex);
38 38
39 return val; 39 return val;
40} 40}
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)
52 if (!buf) 52 if (!buf)
53 return -EINVAL; 53 return -EINVAL;
54 54
55 mutex_lock(&sl->master->mutex); 55 mutex_lock(&sl->master->bus_mutex);
56 dev_dbg(&sl->dev, "mutex locked"); 56 dev_dbg(&sl->dev, "mutex locked");
57 57
58 if (w1_reset_select_slave(sl)) { 58 if (w1_reset_select_slave(sl)) {
59 mutex_unlock(&sl->master->mutex); 59 mutex_unlock(&sl->master->bus_mutex);
60 return -EIO; 60 return -EIO;
61 } 61 }
62 62
@@ -66,7 +66,7 @@ static int _read_reg(struct w1_slave *sl, u8 address, unsigned char* buf)
66 w1_write_block(sl->master, wrbuf, 3); 66 w1_write_block(sl->master, wrbuf, 3);
67 *buf = w1_read_8(sl->master); 67 *buf = w1_read_8(sl->master);
68 68
69 mutex_unlock(&sl->master->mutex); 69 mutex_unlock(&sl->master->bus_mutex);
70 dev_dbg(&sl->dev, "mutex unlocked"); 70 dev_dbg(&sl->dev, "mutex unlocked");
71 return 1; 71 return 1;
72} 72}
@@ -165,7 +165,7 @@ static ssize_t w1_f29_write_output(
165 return -EFAULT; 165 return -EFAULT;
166 166
167 dev_dbg(&sl->dev, "locking mutex for write_output"); 167 dev_dbg(&sl->dev, "locking mutex for write_output");
168 mutex_lock(&sl->master->mutex); 168 mutex_lock(&sl->master->bus_mutex);
169 dev_dbg(&sl->dev, "mutex locked"); 169 dev_dbg(&sl->dev, "mutex locked");
170 170
171 if (w1_reset_select_slave(sl)) 171 if (w1_reset_select_slave(sl))
@@ -200,14 +200,14 @@ static ssize_t w1_f29_write_output(
200 /* read the result of the READ_PIO_REGS command */ 200 /* read the result of the READ_PIO_REGS command */
201 if (w1_read_8(sl->master) == *buf) { 201 if (w1_read_8(sl->master) == *buf) {
202 /* success! */ 202 /* success! */
203 mutex_unlock(&sl->master->mutex); 203 mutex_unlock(&sl->master->bus_mutex);
204 dev_dbg(&sl->dev, 204 dev_dbg(&sl->dev,
205 "mutex unlocked, retries:%d", retries); 205 "mutex unlocked, retries:%d", retries);
206 return 1; 206 return 1;
207 } 207 }
208 } 208 }
209error: 209error:
210 mutex_unlock(&sl->master->mutex); 210 mutex_unlock(&sl->master->bus_mutex);
211 dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries); 211 dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
212 212
213 return -EIO; 213 return -EIO;
@@ -228,7 +228,7 @@ static ssize_t w1_f29_write_activity(
228 if (count != 1 || off != 0) 228 if (count != 1 || off != 0)
229 return -EFAULT; 229 return -EFAULT;
230 230
231 mutex_lock(&sl->master->mutex); 231 mutex_lock(&sl->master->bus_mutex);
232 232
233 if (w1_reset_select_slave(sl)) 233 if (w1_reset_select_slave(sl))
234 goto error; 234 goto error;
@@ -236,7 +236,7 @@ static ssize_t w1_f29_write_activity(
236 while (retries--) { 236 while (retries--) {
237 w1_write_8(sl->master, W1_F29_FUNC_RESET_ACTIVITY_LATCHES); 237 w1_write_8(sl->master, W1_F29_FUNC_RESET_ACTIVITY_LATCHES);
238 if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE) { 238 if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE) {
239 mutex_unlock(&sl->master->mutex); 239 mutex_unlock(&sl->master->bus_mutex);
240 return 1; 240 return 1;
241 } 241 }
242 if (w1_reset_resume_command(sl->master)) 242 if (w1_reset_resume_command(sl->master))
@@ -244,7 +244,7 @@ static ssize_t w1_f29_write_activity(
244 } 244 }
245 245
246error: 246error:
247 mutex_unlock(&sl->master->mutex); 247 mutex_unlock(&sl->master->bus_mutex);
248 return -EIO; 248 return -EIO;
249} 249}
250 250
@@ -263,7 +263,7 @@ static ssize_t w1_f29_write_status_control(
263 if (count != 1 || off != 0) 263 if (count != 1 || off != 0)
264 return -EFAULT; 264 return -EFAULT;
265 265
266 mutex_lock(&sl->master->mutex); 266 mutex_lock(&sl->master->bus_mutex);
267 267
268 if (w1_reset_select_slave(sl)) 268 if (w1_reset_select_slave(sl))
269 goto error; 269 goto error;
@@ -285,12 +285,12 @@ static ssize_t w1_f29_write_status_control(
285 w1_write_block(sl->master, w1_buf, 3); 285 w1_write_block(sl->master, w1_buf, 3);
286 if (w1_read_8(sl->master) == *buf) { 286 if (w1_read_8(sl->master) == *buf) {
287 /* success! */ 287 /* success! */
288 mutex_unlock(&sl->master->mutex); 288 mutex_unlock(&sl->master->bus_mutex);
289 return 1; 289 return 1;
290 } 290 }
291 } 291 }
292error: 292error:
293 mutex_unlock(&sl->master->mutex); 293 mutex_unlock(&sl->master->bus_mutex);
294 294
295 return -EIO; 295 return -EIO;
296} 296}
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,
66 wrbuf[0] = 0xA5; 66 wrbuf[0] = 0xA5;
67 wrbuf[1] = rom_addr & 0xFF; 67 wrbuf[1] = rom_addr & 0xFF;
68 wrbuf[2] = rom_addr >> 8; 68 wrbuf[2] = rom_addr >> 8;
69 mutex_lock(&dev->mutex); 69 mutex_lock(&dev->bus_mutex);
70 if (!w1_reset_select_slave(sl)) { 70 if (!w1_reset_select_slave(sl)) {
71 w1_write_block(dev, wrbuf, 3); 71 w1_write_block(dev, wrbuf, 3);
72 read_byte_count = 0; 72 read_byte_count = 0;
@@ -124,7 +124,7 @@ static ssize_t w1_counter_read(struct device *device,
124 } else { 124 } else {
125 c -= snprintf(out_buf + PAGE_SIZE - c, c, "Connection error"); 125 c -= snprintf(out_buf + PAGE_SIZE - c, c, "Connection error");
126 } 126 }
127 mutex_unlock(&dev->mutex); 127 mutex_unlock(&dev->bus_mutex);
128 return PAGE_SIZE - c; 128 return PAGE_SIZE - c;
129} 129}
130 130
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,
107 if (count == 0) 107 if (count == 0)
108 return 0; 108 return 0;
109 109
110 mutex_lock(&sl->master->mutex); 110 mutex_lock(&sl->master->bus_mutex);
111 111
112 /* read directly from the EEPROM in chunks of W1_F2D_READ_MAXLEN */ 112 /* read directly from the EEPROM in chunks of W1_F2D_READ_MAXLEN */
113 while (todo > 0) { 113 while (todo > 0) {
@@ -126,7 +126,7 @@ static ssize_t w1_f2d_read_bin(struct file *filp, struct kobject *kobj,
126 off += W1_F2D_READ_MAXLEN; 126 off += W1_F2D_READ_MAXLEN;
127 } 127 }
128 128
129 mutex_unlock(&sl->master->mutex); 129 mutex_unlock(&sl->master->bus_mutex);
130 130
131 return count; 131 return count;
132} 132}
@@ -214,7 +214,7 @@ static ssize_t w1_f2d_write_bin(struct file *filp, struct kobject *kobj,
214 if (count == 0) 214 if (count == 0)
215 return 0; 215 return 0;
216 216
217 mutex_lock(&sl->master->mutex); 217 mutex_lock(&sl->master->bus_mutex);
218 218
219 /* Can only write data in blocks of the size of the scratchpad */ 219 /* Can only write data in blocks of the size of the scratchpad */
220 addr = off; 220 addr = off;
@@ -259,7 +259,7 @@ static ssize_t w1_f2d_write_bin(struct file *filp, struct kobject *kobj,
259 } 259 }
260 260
261out_up: 261out_up:
262 mutex_unlock(&sl->master->mutex); 262 mutex_unlock(&sl->master->bus_mutex);
263 263
264 return count; 264 return count;
265} 265}
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,
107 if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0) 107 if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
108 return 0; 108 return 0;
109 109
110 mutex_lock(&sl->master->mutex); 110 mutex_lock(&sl->master->bus_mutex);
111 111
112#ifdef CONFIG_W1_SLAVE_DS2433_CRC 112#ifdef CONFIG_W1_SLAVE_DS2433_CRC
113 113
@@ -138,7 +138,7 @@ static ssize_t w1_f23_read_bin(struct file *filp, struct kobject *kobj,
138#endif /* CONFIG_W1_SLAVE_DS2433_CRC */ 138#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
139 139
140out_up: 140out_up:
141 mutex_unlock(&sl->master->mutex); 141 mutex_unlock(&sl->master->bus_mutex);
142 142
143 return count; 143 return count;
144} 144}
@@ -233,7 +233,7 @@ static ssize_t w1_f23_write_bin(struct file *filp, struct kobject *kobj,
233 } 233 }
234#endif /* CONFIG_W1_SLAVE_DS2433_CRC */ 234#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
235 235
236 mutex_lock(&sl->master->mutex); 236 mutex_lock(&sl->master->bus_mutex);
237 237
238 /* Can only write data to one page at a time */ 238 /* Can only write data to one page at a time */
239 idx = 0; 239 idx = 0;
@@ -251,7 +251,7 @@ static ssize_t w1_f23_write_bin(struct file *filp, struct kobject *kobj,
251 } 251 }
252 252
253out_up: 253out_up:
254 mutex_unlock(&sl->master->mutex); 254 mutex_unlock(&sl->master->bus_mutex);
255 255
256 return count; 256 return count;
257} 257}
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,
31 if (!dev) 31 if (!dev)
32 return 0; 32 return 0;
33 33
34 mutex_lock(&sl->master->mutex); 34 mutex_lock(&sl->master->bus_mutex);
35 35
36 if (addr > DS2760_DATA_SIZE || addr < 0) { 36 if (addr > DS2760_DATA_SIZE || addr < 0) {
37 count = 0; 37 count = 0;
@@ -54,7 +54,7 @@ static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
54 } 54 }
55 55
56out: 56out:
57 mutex_unlock(&sl->master->mutex); 57 mutex_unlock(&sl->master->bus_mutex);
58 58
59 return count; 59 return count;
60} 60}
@@ -76,14 +76,14 @@ static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
76 if (!dev) 76 if (!dev)
77 return -EINVAL; 77 return -EINVAL;
78 78
79 mutex_lock(&sl->master->mutex); 79 mutex_lock(&sl->master->bus_mutex);
80 80
81 if (w1_reset_select_slave(sl) == 0) { 81 if (w1_reset_select_slave(sl) == 0) {
82 w1_write_8(sl->master, cmd); 82 w1_write_8(sl->master, cmd);
83 w1_write_8(sl->master, addr); 83 w1_write_8(sl->master, addr);
84 } 84 }
85 85
86 mutex_unlock(&sl->master->mutex); 86 mutex_unlock(&sl->master->bus_mutex);
87 return 0; 87 return 0;
88} 88}
89 89
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,
60 if (!dev) 60 if (!dev)
61 return -ENODEV; 61 return -ENODEV;
62 62
63 mutex_lock(&sl->master->mutex); 63 mutex_lock(&sl->master->bus_mutex);
64 64
65 ret = w1_ds2780_do_io(dev, buf, addr, count, io); 65 ret = w1_ds2780_do_io(dev, buf, addr, count, io);
66 66
67 mutex_unlock(&sl->master->mutex); 67 mutex_unlock(&sl->master->bus_mutex);
68 68
69 return ret; 69 return ret;
70} 70}
71EXPORT_SYMBOL(w1_ds2780_io); 71EXPORT_SYMBOL(w1_ds2780_io);
72 72
73int w1_ds2780_io_nolock(struct device *dev, char *buf, int addr, size_t count,
74 int io)
75{
76 int ret;
77
78 if (!dev)
79 return -ENODEV;
80
81 ret = w1_ds2780_do_io(dev, buf, addr, count, io);
82
83 return ret;
84}
85EXPORT_SYMBOL(w1_ds2780_io_nolock);
86
87int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd) 73int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
88{ 74{
89 struct w1_slave *sl = container_of(dev, struct w1_slave, dev); 75 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)
91 if (!dev) 77 if (!dev)
92 return -EINVAL; 78 return -EINVAL;
93 79
94 mutex_lock(&sl->master->mutex); 80 mutex_lock(&sl->master->bus_mutex);
95 81
96 if (w1_reset_select_slave(sl) == 0) { 82 if (w1_reset_select_slave(sl) == 0) {
97 w1_write_8(sl->master, cmd); 83 w1_write_8(sl->master, cmd);
98 w1_write_8(sl->master, addr); 84 w1_write_8(sl->master, addr);
99 } 85 }
100 86
101 mutex_unlock(&sl->master->mutex); 87 mutex_unlock(&sl->master->bus_mutex);
102 return 0; 88 return 0;
103} 89}
104EXPORT_SYMBOL(w1_ds2780_eeprom_cmd); 90EXPORT_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 @@
124 124
125extern int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count, 125extern int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
126 int io); 126 int io);
127extern int w1_ds2780_io_nolock(struct device *dev, char *buf, int addr,
128 size_t count, int io);
129extern int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd); 127extern int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd);
130 128
131#endif /* !_W1_DS2780_H */ 129#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,
58 if (!dev) 58 if (!dev)
59 return -ENODEV; 59 return -ENODEV;
60 60
61 mutex_lock(&sl->master->mutex); 61 mutex_lock(&sl->master->bus_mutex);
62 62
63 ret = w1_ds2781_do_io(dev, buf, addr, count, io); 63 ret = w1_ds2781_do_io(dev, buf, addr, count, io);
64 64
65 mutex_unlock(&sl->master->mutex); 65 mutex_unlock(&sl->master->bus_mutex);
66 66
67 return ret; 67 return ret;
68} 68}
69EXPORT_SYMBOL(w1_ds2781_io); 69EXPORT_SYMBOL(w1_ds2781_io);
70 70
71int w1_ds2781_io_nolock(struct device *dev, char *buf, int addr, size_t count,
72 int io)
73{
74 int ret;
75
76 if (!dev)
77 return -ENODEV;
78
79 ret = w1_ds2781_do_io(dev, buf, addr, count, io);
80
81 return ret;
82}
83EXPORT_SYMBOL(w1_ds2781_io_nolock);
84
85int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd) 71int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd)
86{ 72{
87 struct w1_slave *sl = container_of(dev, struct w1_slave, dev); 73 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)
89 if (!dev) 75 if (!dev)
90 return -EINVAL; 76 return -EINVAL;
91 77
92 mutex_lock(&sl->master->mutex); 78 mutex_lock(&sl->master->bus_mutex);
93 79
94 if (w1_reset_select_slave(sl) == 0) { 80 if (w1_reset_select_slave(sl) == 0) {
95 w1_write_8(sl->master, cmd); 81 w1_write_8(sl->master, cmd);
96 w1_write_8(sl->master, addr); 82 w1_write_8(sl->master, addr);
97 } 83 }
98 84
99 mutex_unlock(&sl->master->mutex); 85 mutex_unlock(&sl->master->bus_mutex);
100 return 0; 86 return 0;
101} 87}
102EXPORT_SYMBOL(w1_ds2781_eeprom_cmd); 88EXPORT_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 @@
129 129
130extern int w1_ds2781_io(struct device *dev, char *buf, int addr, size_t count, 130extern int w1_ds2781_io(struct device *dev, char *buf, int addr, size_t count,
131 int io); 131 int io);
132extern int w1_ds2781_io_nolock(struct device *dev, char *buf, int addr,
133 size_t count, int io);
134extern int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd); 132extern int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd);
135 133
136#endif /* !_W1_DS2781_H */ 134#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,
179 int i, max_trying = 10; 179 int i, max_trying = 10;
180 ssize_t c = PAGE_SIZE; 180 ssize_t c = PAGE_SIZE;
181 181
182 i = mutex_lock_interruptible(&dev->mutex); 182 i = mutex_lock_interruptible(&dev->bus_mutex);
183 if (i != 0) 183 if (i != 0)
184 return i; 184 return i;
185 185
@@ -207,19 +207,19 @@ static ssize_t w1_therm_read(struct device *device,
207 w1_write_8(dev, W1_CONVERT_TEMP); 207 w1_write_8(dev, W1_CONVERT_TEMP);
208 208
209 if (external_power) { 209 if (external_power) {
210 mutex_unlock(&dev->mutex); 210 mutex_unlock(&dev->bus_mutex);
211 211
212 sleep_rem = msleep_interruptible(tm); 212 sleep_rem = msleep_interruptible(tm);
213 if (sleep_rem != 0) 213 if (sleep_rem != 0)
214 return -EINTR; 214 return -EINTR;
215 215
216 i = mutex_lock_interruptible(&dev->mutex); 216 i = mutex_lock_interruptible(&dev->bus_mutex);
217 if (i != 0) 217 if (i != 0)
218 return i; 218 return i;
219 } else if (!w1_strong_pullup) { 219 } else if (!w1_strong_pullup) {
220 sleep_rem = msleep_interruptible(tm); 220 sleep_rem = msleep_interruptible(tm);
221 if (sleep_rem != 0) { 221 if (sleep_rem != 0) {
222 mutex_unlock(&dev->mutex); 222 mutex_unlock(&dev->bus_mutex);
223 return -EINTR; 223 return -EINTR;
224 } 224 }
225 } 225 }
@@ -258,7 +258,7 @@ static ssize_t w1_therm_read(struct device *device,
258 258
259 c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n", 259 c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
260 w1_convert_temp(rom, sl->family->fid)); 260 w1_convert_temp(rom, sl->family->fid));
261 mutex_unlock(&dev->mutex); 261 mutex_unlock(&dev->bus_mutex);
262 262
263 return PAGE_SIZE - c; 263 return PAGE_SIZE - c;
264} 264}
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
885 * 885 *
886 * Return 0 - device(s) present, 1 - no devices present. 886 * Return 0 - device(s) present, 1 - no devices present.
887 */ 887 */
888 mutex_lock(&dev->bus_mutex);
888 if (w1_reset_bus(dev)) { 889 if (w1_reset_bus(dev)) {
890 mutex_unlock(&dev->bus_mutex);
889 dev_dbg(&dev->dev, "No devices present on the wire.\n"); 891 dev_dbg(&dev->dev, "No devices present on the wire.\n");
890 break; 892 break;
891 } 893 }
892 894
893 /* Do fast search on single slave bus */ 895 /* Do fast search on single slave bus */
894 if (dev->max_slave_count == 1) { 896 if (dev->max_slave_count == 1) {
897 int rv;
895 w1_write_8(dev, W1_READ_ROM); 898 w1_write_8(dev, W1_READ_ROM);
899 rv = w1_read_block(dev, (u8 *)&rn, 8);
900 mutex_unlock(&dev->bus_mutex);
896 901
897 if (w1_read_block(dev, (u8 *)&rn, 8) == 8 && rn) 902 if (rv == 8 && rn)
898 cb(dev, rn); 903 cb(dev, rn);
899 904
900 break; 905 break;
@@ -927,10 +932,12 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
927 rn |= (tmp64 << i); 932 rn |= (tmp64 << i);
928 933
929 if (kthread_should_stop()) { 934 if (kthread_should_stop()) {
935 mutex_unlock(&dev->bus_mutex);
930 dev_dbg(&dev->dev, "Abort w1_search\n"); 936 dev_dbg(&dev->dev, "Abort w1_search\n");
931 return; 937 return;
932 } 938 }
933 } 939 }
940 mutex_unlock(&dev->bus_mutex);
934 941
935 if ( (triplet_ret & 0x03) != 0x03 ) { 942 if ( (triplet_ret & 0x03) != 0x03 ) {
936 if ( (desc_bit == last_zero) || (last_zero < 0)) 943 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
180 180
181 struct task_struct *thread; 181 struct task_struct *thread;
182 struct mutex mutex; 182 struct mutex mutex;
183 struct mutex bus_mutex;
183 184
184 struct device_driver *driver; 185 struct device_driver *driver;
185 struct device dev; 186 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,
76 76
77 INIT_LIST_HEAD(&dev->slist); 77 INIT_LIST_HEAD(&dev->slist);
78 mutex_init(&dev->mutex); 78 mutex_init(&dev->mutex);
79 mutex_init(&dev->bus_mutex);
79 80
80 memcpy(&dev->dev, device, sizeof(struct device)); 81 memcpy(&dev->dev, device, sizeof(struct device));
81 dev_set_name(&dev->dev, "w1_bus_master%u", dev->id); 82 dev_set_name(&dev->dev, "w1_bus_master%u", dev->id);