--- /dev/null
+Index: linux-2.6.38-rc6/drivers/cbus/retu.c
+===================================================================
+--- linux-2.6.38-rc6.orig/drivers/cbus/retu.c 2011-02-26 23:23:34.014429906 +0100
++++ linux-2.6.38-rc6/drivers/cbus/retu.c 2011-02-26 23:25:18.905358127 +0100
+@@ -120,7 +120,9 @@
+ {
+ struct retu *retu = dev_get_drvdata(child->parent);
+
++ mutex_lock(&retu->mutex);
+ __retu_write_reg(retu, reg, val);
++ mutex_unlock(&retu->mutex);
+ }
+ EXPORT_SYMBOL_GPL(retu_write_reg);
+
+++ /dev/null
-Index: linux-2.6.38-rc6/drivers/cbus/retu.c
-===================================================================
---- linux-2.6.38-rc6.orig/drivers/cbus/retu.c 2011-02-26 23:23:34.014429906 +0100
-+++ linux-2.6.38-rc6/drivers/cbus/retu.c 2011-02-26 23:25:18.905358127 +0100
-@@ -120,7 +120,9 @@
- {
- struct retu *retu = dev_get_drvdata(child->parent);
-
-+ mutex_lock(&retu->mutex);
- __retu_write_reg(retu, reg, val);
-+ mutex_unlock(&retu->mutex);
- }
- EXPORT_SYMBOL_GPL(retu_write_reg);
-