1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index c7c64f18773d..fa932c2f7d97 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -613,6 +613,9 @@ static int w1_bus_notify(struct notifier_block *nb, unsigned long action,
         sl = dev_to_w1_slave(dev);
         fops = sl->family->fops;
 
+        if (!fops)
+                return 0;
+
         switch (action) {
         case BUS_NOTIFY_ADD_DEVICE:
                 /* if the family driver needs to initialize something... */
@@ -713,7 +716,10 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
         atomic_set(&sl->refcnt, 0);
         init_completion(&sl->released);
 
+        /* slave modules need to be loaded in a context with unlocked mutex */
+        mutex_unlock(&dev->mutex);
         request_module("w1-family-0x%0x", rn->family);
+        mutex_lock(&dev->mutex);
 
         spin_lock(&w1_flock);
         f = w1_family_registered(rn->family);