linux-kernel - [PATCH 2/2] w1 - call request_module with w1 master mutex unlocked

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Message-ID: <2740843.j7PY66riEd@maximilian>
Date:	Sun, 06 Oct 2013 21:13:40 +0200
From:	Hans-Frieder Vogt <hfvogt@....net>
To:	zbr@...emap.net, gregkh@...uxfoundation.org
Cc:	linux-kernel@...r.kernel.org
Subject: [PATCH 2/2] 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 <hfvogt@....net>
---
 drivers/w1/w1.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/w1/w1.c	2013-10-06 14:58:45.246528318 +0200
+++ b/drivers/w1/w1.c	2013-10-06 19:13:04.115279322 +0200
@@ -716,7 +716,10 @@ 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);

Hans-Frieder Vogt                       e-mail: hfvogt <at> gmx .dot. net

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