sync: change wait timeout to mirror poll semantics

Change-Id: Ib38e6d339d41885a33027752690d65a52b6897f6
Signed-off-by: Erik Gilling <konkers@android.com>
Signed-off-by: Ajay Dudani <adudani@codeaurora.org>
diff --git a/drivers/base/sync.c b/drivers/base/sync.c
index ad3fee0..793a289 100644
--- a/drivers/base/sync.c
+++ b/drivers/base/sync.c
@@ -560,14 +560,14 @@
 
 int sync_fence_wait(struct sync_fence *fence, long timeout)
 {
-	int err;
+	int err = 0;
 
-	if (timeout) {
+	if (timeout > 0) {
 		timeout = msecs_to_jiffies(timeout);
 		err = wait_event_interruptible_timeout(fence->wq,
 						       fence->status != 0,
 						       timeout);
-	} else {
+	} else if (timeout < 0{
 		err = wait_event_interruptible(fence->wq, fence->status != 0);
 	}
 
diff --git a/include/linux/sync.h b/include/linux/sync.h
index 15863a6..75ed5f1 100644
--- a/include/linux/sync.h
+++ b/include/linux/sync.h
@@ -329,8 +329,8 @@
  * @fence:	fence to wait on
  * @tiemout:	timeout in ms
  *
- * Wait for @fence to be signaled or have an error.  Waits indefintly
- * if @timeout = 0
+ * Wait for @fence to be signaled or have an error.  Waits indefinitely
+ * if @timeout < 0
  */
 int sync_fence_wait(struct sync_fence *fence, long timeout);
 
@@ -389,9 +389,9 @@
 /**
  * DOC: SYNC_IOC_WAIT - wait for a fence to signal
  *
- * pass timeout in milliseconds.
+ * pass timeout in milliseconds.  Waits indefinitely timeout < 0.
  */
-#define SYNC_IOC_WAIT		_IOW(SYNC_IOC_MAGIC, 0, __u32)
+#define SYNC_IOC_WAIT		_IOW(SYNC_IOC_MAGIC, 0, __s32)
 
 /**
  * DOC: SYNC_IOC_MERGE - merge two fences