From: Blaise Gassend <blaise@willowgarage.com>
Date: Fri, 22 Oct 2010 09:32:04 +0000 (-0700)
Subject: compat: Fixes missing sem member in struct device for RT PREEMPT prior to 2.6.34
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=4bf6730eac2ce1fb1610c9a4be822a2c738f379a;p=openwrt%2Fstaging%2Fblogic.git

compat: Fixes missing sem member in struct device for RT PREEMPT prior to 2.6.34

The RT PREEMPT patch eliminates the sem member in struct device
breaking device_lock, device_unlock and device_trylock in kernels
prior to 2.6.34. The attached patch replaces the use of sem by a use
of mutex.

Signed-off-by: Blaise Gassend <blaise@willowgarage.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
---

diff --git a/include/linux/compat-2.6.34.h b/include/linux/compat-2.6.34.h
index 336c61b26169..1cfd6e5cda13 100644
--- a/include/linux/compat-2.6.34.h
+++ b/include/linux/compat-2.6.34.h
@@ -142,17 +142,32 @@ do {								\
 
 static inline void device_lock(struct device *dev)
 {
+#if defined(CONFIG_NONE) || defined(CONFIG_PREEMPT_RT) || \
+    defined(CONFIG_PREEMPT_VOLUNTARY) || defined(CONFIG_PREEMPT_DESKTOP)
+        mutex_lock(&dev->parent->mutex);
+#else
 	down(&dev->sem);
+#endif
 }
 
 static inline int device_trylock(struct device *dev)
 {
+#if defined(CONFIG_NONE) || defined(CONFIG_PREEMPT_RT) || \
+    defined(CONFIG_PREEMPT_VOLUNTARY) || defined(CONFIG_PREEMPT_DESKTOP)
+	return mutex_trylock(&dev->mutex);
+#else
 	return down_trylock(&dev->sem);
+#endif
 }
 
 static inline void device_unlock(struct device *dev)
 {
+#if defined(CONFIG_NONE) || defined(CONFIG_PREEMPT_RT) || \
+    defined(CONFIG_PREEMPT_VOLUNTARY) || defined(CONFIG_PREEMPT_DESKTOP)
+        mutex_unlock(&dev->mutex);
+#else
 	up(&dev->sem);
+#endif
 }
 
 #if defined(CONFIG_PCMCIA) || defined(CONFIG_PCMCIA_MODULE)