hwcomposer: clarify vsync timestamp meaning
This change clarifies the meaning of the HWC vsync timestamp to specify that
the timestamp must be relative to the system monotonic clock.
Change-Id: I4386ce90511fd5b8f8e988917da637d84d86f026
diff --git a/include/hardware/hwcomposer.h b/include/hardware/hwcomposer.h
index 61ee736..cb8ac9b 100644
--- a/include/hardware/hwcomposer.h
+++ b/include/hardware/hwcomposer.h
@@ -322,8 +322,8 @@
* received and HWC_EVENT_VSYNC is enabled (see: hwc_event_control).
*
* the "zero" parameter must always be 0.
- * the "timestamp" parameter is the timestamp in nanosecond of when the
- * vsync event happened.
+ * the "timestamp" parameter is the system monotonic clock timestamp in
+ * nanosecond of when the vsync event happened.
*
* vsync() is GUARANTEED TO NOT CALL BACK into the h/w composer HAL.
*