Merge branch 'android-4.4-p' of https://android.googlesource.com/kernel/common into lineage-18.1-caf-msm8998

This brings LA.UM.9.2.r1-01800-SDMxx0.0 up to date with
https://android.googlesource.com/kernel/common/ android-4.4-p at commit:
300d539b8e6e2 ANDROID: usb: f_accessory: Wrap '_acc_dev' in get()/put() accessors

Conflicts:
	drivers/usb/gadget/function/f_accessory.c
	include/linux/spi/spi.h

Change-Id: Ifef5bfcb9d92b6d560126f0216369c567476f55d

5 files changed, 42 insertions, 14 deletions

diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index 266f446ba331..8bbd887ca422 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -114,18 +114,22 @@ EXPORT_SYMBOL_GPL(xenbus_strstate);
  */
 int xenbus_watch_path(struct xenbus_device *dev, const char *path,
 		      struct xenbus_watch *watch,
+		      bool (*will_handle)(struct xenbus_watch *,
+					  const char **, unsigned int),
 		      void (*callback)(struct xenbus_watch *,
 				       const char **, unsigned int))
 {
 	int err;
 
 	watch->node = path;
+	watch->will_handle = will_handle;
 	watch->callback = callback;
 
 	err = register_xenbus_watch(watch);
 
 	if (err) {
 		watch->node = NULL;
+		watch->will_handle = NULL;
 		watch->callback = NULL;
 		xenbus_dev_fatal(dev, err, "adding watch on %s", path);
 	}
@@ -152,6 +156,8 @@ EXPORT_SYMBOL_GPL(xenbus_watch_path);
  */
 int xenbus_watch_pathfmt(struct xenbus_device *dev,
 			 struct xenbus_watch *watch,
+			 bool (*will_handle)(struct xenbus_watch *,
+					     const char **, unsigned int),
 			 void (*callback)(struct xenbus_watch *,
 					const char **, unsigned int),
 			 const char *pathfmt, ...)
@@ -168,7 +174,7 @@ int xenbus_watch_pathfmt(struct xenbus_device *dev,
 		xenbus_dev_fatal(dev, -ENOMEM, "allocating path for watch");
 		return -ENOMEM;
 	}
-	err = xenbus_watch_path(dev, path, watch, callback);
+	err = xenbus_watch_path(dev, path, watch, will_handle, callback);
 
 	if (err)
 		kfree(path);
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index c2d447687e33..ba7590d75985 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -137,6 +137,7 @@ static int watch_otherend(struct xenbus_device *dev)
 		container_of(dev->dev.bus, struct xen_bus_type, bus);
 
 	return xenbus_watch_pathfmt(dev, &dev->otherend_watch,
+				    bus->otherend_will_handle,
 				    bus->otherend_changed,
 				    "%s/%s", dev->otherend, "state");
 }
diff --git a/drivers/xen/xenbus/xenbus_probe.h b/drivers/xen/xenbus/xenbus_probe.h
index c9ec7ca1f7ab..2c394c6ba605 100644
--- a/drivers/xen/xenbus/xenbus_probe.h
+++ b/drivers/xen/xenbus/xenbus_probe.h
@@ -42,6 +42,8 @@ struct xen_bus_type {
 	int (*get_bus_id)(char bus_id[XEN_BUS_ID_SIZE], const char *nodename);
 	int (*probe)(struct xen_bus_type *bus, const char *type,
 		     const char *dir);
+	bool (*otherend_will_handle)(struct xenbus_watch *watch,
+				     const char **vec, unsigned int len);
 	void (*otherend_changed)(struct xenbus_watch *watch, const char **vec,
 				 unsigned int len);
 	struct bus_type bus;
diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c
index 04f7f85a5edf..597c0b038454 100644
--- a/drivers/xen/xenbus/xenbus_probe_backend.c
+++ b/drivers/xen/xenbus/xenbus_probe_backend.c
@@ -181,6 +181,12 @@ static int xenbus_probe_backend(struct xen_bus_type *bus, const char *type,
 	return err;
 }
 
+static bool frontend_will_handle(struct xenbus_watch *watch,
+				 const char **vec, unsigned int len)
+{
+	return watch->nr_pending == 0;
+}
+
 static void frontend_changed(struct xenbus_watch *watch,
 			    const char **vec, unsigned int len)
 {
@@ -192,6 +198,7 @@ static struct xen_bus_type xenbus_backend = {
 	.levels = 3,		/* backend/type/<frontend>/<id> */
 	.get_bus_id = backend_bus_id,
 	.probe = xenbus_probe_backend,
+	.otherend_will_handle = frontend_will_handle,
 	.otherend_changed = frontend_changed,
 	.bus = {
 		.name		= "xen-backend",
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index ce65591b4168..d98d88fae58a 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -701,6 +701,8 @@ int register_xenbus_watch(struct xenbus_watch *watch)
 
 	sprintf(token, "%lX", (long)watch);
 
+	watch->nr_pending = 0;
+
 	down_read(&xs_state.watch_mutex);
 
 	spin_lock(&watches_lock);
@@ -750,12 +752,15 @@ void unregister_xenbus_watch(struct xenbus_watch *watch)
 
 	/* Cancel pending watch events. */
 	spin_lock(&watch_events_lock);
-	list_for_each_entry_safe(msg, tmp, &watch_events, list) {
-		if (msg->u.watch.handle != watch)
-			continue;
-		list_del(&msg->list);
-		kfree(msg->u.watch.vec);
-		kfree(msg);
+	if (watch->nr_pending) {
+		list_for_each_entry_safe(msg, tmp, &watch_events, list) {
+			if (msg->u.watch.handle != watch)
+				continue;
+			list_del(&msg->list);
+			kfree(msg->u.watch.vec);
+			kfree(msg);
+		}
+		watch->nr_pending = 0;
 	}
 	spin_unlock(&watch_events_lock);
 
@@ -802,7 +807,6 @@ void xs_suspend_cancel(void)
 
 static int xenwatch_thread(void *unused)
 {
-	struct list_head *ent;
 	struct xs_stored_msg *msg;
 
 	for (;;) {
@@ -815,13 +819,15 @@ static int xenwatch_thread(void *unused)
 		mutex_lock(&xenwatch_mutex);
 
 		spin_lock(&watch_events_lock);
-		ent = watch_events.next;
-		if (ent != &watch_events)
-			list_del(ent);
+		msg = list_first_entry_or_null(&watch_events,
+				struct xs_stored_msg, list);
+		if (msg) {
+			list_del(&msg->list);
+			msg->u.watch.handle->nr_pending--;
+		}
 		spin_unlock(&watch_events_lock);
 
-		if (ent != &watch_events) {
-			msg = list_entry(ent, struct xs_stored_msg, list);
+		if (msg) {
 			msg->u.watch.handle->callback(
 				msg->u.watch.handle,
 				(const char **)msg->u.watch.vec,
@@ -903,9 +909,15 @@ static int process_msg(void)
 		spin_lock(&watches_lock);
 		msg->u.watch.handle = find_watch(
 			msg->u.watch.vec[XS_WATCH_TOKEN]);
-		if (msg->u.watch.handle != NULL) {
+		if (msg->u.watch.handle != NULL &&
+				(!msg->u.watch.handle->will_handle ||
+				 msg->u.watch.handle->will_handle(
+					 msg->u.watch.handle,
+					 (const char **)msg->u.watch.vec,
+					 msg->u.watch.vec_size))) {
 			spin_lock(&watch_events_lock);
 			list_add_tail(&msg->list, &watch_events);
+			msg->u.watch.handle->nr_pending++;
 			wake_up(&watch_events_waitq);
 			spin_unlock(&watch_events_lock);
 		} else {