From: Riley Andrews <riandrews@google.com>
Date: Wed, 14 Oct 2015 18:54:15 +0000 (-0700)
Subject: Revert "android: binder: Change binder mutex to rtmutex."
X-Git-Tag: firefly_0821_release~3678^2~1
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=35d9cc3d716849666b4dc12280272c517e5dd4b6;p=firefly-linux-kernel-4.4.55.git

Revert "android: binder: Change binder mutex to rtmutex."

This reverts commit ebce7cd30b3e00232c8be23d0f04d7c0599089b5.

This ends up doing more damage than good on most devices. Go back to
using a standard mutex.

(cherry picked from commit ea93186577de4fae3a2273c296bfcf1839048df0)
---

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 383aa21a0e2a..83af691b5840 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -26,7 +26,6 @@
 #include <linux/miscdevice.h>
 #include <linux/mm.h>
 #include <linux/module.h>
-#include <linux/rtmutex.h>
 #include <linux/mutex.h>
 #include <linux/nsproxy.h>
 #include <linux/poll.h>
@@ -47,7 +46,7 @@
 #include <uapi/linux/android/binder.h>
 #include "binder_trace.h"
 
-static DEFINE_RT_MUTEX(binder_main_lock);
+static DEFINE_MUTEX(binder_main_lock);
 static DEFINE_MUTEX(binder_deferred_lock);
 static DEFINE_MUTEX(binder_mmap_lock);
 
@@ -427,14 +426,14 @@ static long task_close_fd(struct binder_proc *proc, unsigned int fd)
 static inline void binder_lock(const char *tag)
 {
 	trace_binder_lock(tag);
-	rt_mutex_lock(&binder_main_lock);
+	mutex_lock(&binder_main_lock);
 	trace_binder_locked(tag);
 }
 
 static inline void binder_unlock(const char *tag)
 {
 	trace_binder_unlock(tag);
-	rt_mutex_unlock(&binder_main_lock);
+	mutex_unlock(&binder_main_lock);
 }
 
 static void binder_set_nice(long nice)