intel: comment on semaphores
diff --git a/icd/intel/dispatch_tables.c b/icd/intel/dispatch_tables.c
index c2e1a21..a0e12a2 100644
--- a/icd/intel/dispatch_tables.c
+++ b/icd/intel/dispatch_tables.c
@@ -109,6 +109,15 @@
const XGL_QUEUE_SEMAPHORE_CREATE_INFO* pCreateInfo,
XGL_QUEUE_SEMAPHORE* pSemaphore)
{
+
+ /*
+ * We want to find an unused semaphore register and initialize it. Signal
+ * will increment the register. Wait will atomically decrement it and
+ * block if the value is zero, or a large constant N if we do not want to
+ * go negative.
+ *
+ * XXX However, MI_SEMAPHORE_MBOX does not seem to have the flexibility.
+ */
return XGL_ERROR_UNAVAILABLE;
}