w1: use correct lock on error in w1_seq_show()

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>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index 3351be66795752a8414c87f349cd2647ce337630..2f029e8f4f95d7fbc15a2af11f2b8e28abce7e34 100644 (file)
--- 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;