[PATCH 3.11 60/66] w1 - call request_module with w1 master mutex unlocked

[Greg Kroah-Hartman]

3.11-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Hans-Frieder Vogt <hfvogt@xxxxxxx>

commit bc04d76d6942068f75c10790072280b847ec6f1f upstream.

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 <hfvogt@xxxxxxx>
Acked-by: Evgeniy Polyakov <zbr@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/w1/w1.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -680,7 +680,10 @@ static int w1_attach_slave_device(struct
 	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);


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