staging: sync: Add timestamps to sync_pts

Add ktime timestamps to sync_pt structure and
update them when signaled

Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Erik Gilling <konkers@android.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Rob Clark <robclark@gmail.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: dri-devel@lists.freedesktop.org
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Erik Gilling <konkers@android.com>
[jstultz: Added commit message]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/sync.c

@@ -155,12 +155,17 @@ void sync_pt_free(struct sync_pt *pt)
 /* call with pt->parent->active_list_lock held */
 static int _sync_pt_has_signaled(struct sync_pt *pt)
 {
+	int old_status = pt->status;
+
 	if (!pt->status)
 		pt->status = pt->parent->ops->has_signaled(pt);
 
 	if (!pt->status && pt->parent->destroyed)
 		pt->status = -ENOENT;
 
+	if (pt->status != old_status)
+		pt->timestamp = ktime_get();
+
 	return pt->status;
 }
 

drivers/staging/android/sync.h

@@ -16,6 +16,7 @@
 #include <linux/types.h>
 #ifdef __KERNEL__
 
+#include <linux/ktime.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/wait.h>
@@ -90,6 +91,8 @@ struct sync_timeline {
  * @fence:		sync_fence to which the sync_pt belongs
  * @pt_list:		membership in sync_fence.pt_list_head
  * @status:		1: signaled, 0:active, <0: error
+ * @timestamp:		time which sync_pt status transitioned from active to
+ *			  singaled or error.
  */
 struct sync_pt {
 	struct sync_timeline		*parent;
@@ -102,6 +105,8 @@ struct sync_pt {
 
 	/* protected by parent->active_list_lock */
 	int			status;
+
+	ktime_t			timestamp;
 };
 
 /**