w1_bq27000: Only one thread can access the bq27000 at a time.
authorNeilBrown <neilb@suse.de>
Sun, 19 Feb 2012 02:10:00 +0000 (13:10 +1100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 24 Feb 2012 22:25:50 +0000 (14:25 -0800)
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>
drivers/w1/slaves/w1_bq27000.c

index 6ae60aa1315b17685e27d66e9a4ad9b9e66132b7..52ad812fa1e7e73c8bc07545b82e967c73ff6a50 100644 (file)
@@ -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;
 }