w1 - call request_module with w1 master mutex unlocked

request_module for w1 slave modules needs to be called with the w1 master mutex unlocked. Because w1_attach_slave_device gets always(?) called with mutex locked, we need to temporarily unlock the w1 master mutex for the loading of the w1 slave module. Signed-off by: Hans-Frieder Vogt <[email protected]> Acked-by: Evgeniy Polyakov <[email protected]> Cc: stable <[email protected]> # 3.11+ Signed-off-by: Greg Kroah-Hartman <[email protected]>
torvalds · Oct 7, 2013 · bc04d76 · bc04d76
1 parent 2962aec
commit bc04d76
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
@@ -716,7 +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);