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authorNeilBrown <neilb@suse.de>2012-02-19 13:10:00 +1100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-02-24 14:25:50 -0800
commitf6e8a1d7b4c4087e13913da43deb45b3e3413f29 (patch)
tree412aeb428f3cf9a9817e000031920481a20a8f40 /drivers/w1
parentdf7019f37053bb5357907ec2d1fd516304f38348 (diff)
w1_bq27000: Only one thread can access the bq27000 at a time.
If multiple threads try, they trip over each other badly. 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/slaves/w1_bq27000.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/w1/slaves/w1_bq27000.c b/drivers/w1/slaves/w1_bq27000.c
index 6ae60aa1315..52ad812fa1e 100644
--- a/drivers/w1/slaves/w1_bq27000.c
+++ b/drivers/w1/slaves/w1_bq27000.c
@@ -31,8 +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);
w1_write_8(sl->master, HDQ_CMD_READ | reg);
val = w1_read_8(sl->master);
+ mutex_unlock(&sl->master->mutex);
return val;
}