[patch] [patch 2/2 v2] w1: use correct lock on error in w1_seq_show()

Dan Carpenter
2015-06-04T09:05:03Z

I noticed there was a problem here because Smatch complained:

drivers/w1/slaves/w1_therm.c:416 w1_seq_show() warn:
inconsistent returns 'mutex:&sl->master->mutex'.
Locked on: line 416
Unlocked on: line 413

The problem is that we lock ->mutex but we unlock ->bus_mutex on error.
David Fries says that ->bus_mutex is correct and ->mutex is incorrect.

Fixes: d9411e57dc7f ('w1: Add support for DS28EA00 sequence to w1-therm')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: In the first version I changed ->bus_mutext to ->mutex instead of
the other way around.

diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index d21e686..06b034c 100644
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -355,7 +355,7 @@ static ssize_t w1_seq_show(struct device *device,
struct w1_reg_num *reg_num;
int seq = 0;

- mutex_lock(&sl->master->mutex);
+ mutex_lock(&sl->master->bus_mutex);
/* Place all devices in CHAIN state */
if (w1_reset_bus(sl->master))
goto error;
@@ -407,7 +407,7 @@ static ssize_t w1_seq_show(struct device *device,
ack = w1_read_8(sl->master);
if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
goto error;
- mutex_unlock(&sl->master->mutex);
+ mutex_unlock(&sl->master->bus_mutex);

c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq);
return PAGE_SIZE - c;