hwcomposer: Specify set() call error behavior.
Bug: 7308829
Change-Id: Ibab6f0d2929860f02c17d6ffadb326fc0c333c4d
diff --git a/include/hardware/hwcomposer.h b/include/hardware/hwcomposer.h
index f03ac70..0722e32 100644
--- a/include/hardware/hwcomposer.h
+++ b/include/hardware/hwcomposer.h
@@ -407,13 +407,20 @@
* non-NULL. In HWC 1.2, support for one virtual display is required, and
* no more than one will be used. Future HWC versions might require more.
*
- * IMPORTANT NOTE: there is an implicit layer containing opaque black
+ * IMPORTANT NOTE: There is an implicit layer containing opaque black
* pixels behind all the layers in the list. It is the responsibility of
* the hwcomposer module to make sure black pixels are output (or blended
* from).
*
- * returns: 0 on success. An negative error code on error:
- * HWC_EGL_ERROR: eglGetError() will provide the proper error code
+ * IMPORTANT NOTE: In the event of an error this call *MUST* still cause
+ * any fences returned in the previous call to set to eventually become
+ * signaled. The caller may have already issued wait commands on these
+ * fences, and having set return without causing those fences to signal
+ * will likely result in a deadlock.
+ *
+ * returns: 0 on success. A negative error code on error:
+ * HWC_EGL_ERROR: eglGetError() will provide the proper error code (only
+ * allowed prior to HWComposer 1.1)
* Another code for non EGL errors.
*/
int (*set)(struct hwc_composer_device_1 *dev,