From 554cd8bcc2bc9664cfea0e360571e92a528dc06a Mon Sep 17 00:00:00 2001
From: Emma Anholt <emma@anholt.net>
Date: Mon, 22 Aug 2022 09:35:13 -0700
Subject: [PATCH] freedreno/regs: Add a bit of documentation of what SKIP_IB2
 does.

Based on @cwabbott's research.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18187>
---
 src/freedreno/registers/adreno/adreno_pm4.xml | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/freedreno/registers/adreno/adreno_pm4.xml b/src/freedreno/registers/adreno/adreno_pm4.xml
index 040a1b32eaf..da5da1e5e89 100644
--- a/src/freedreno/registers/adreno/adreno_pm4.xml
+++ b/src/freedreno/registers/adreno/adreno_pm4.xml
@@ -412,6 +412,12 @@ xsi:schemaLocation="http://nouveau.freedesktop.org/ rules-ng.xsd">
 	<value name="CP_CONTEXT_REG_BUNCH" value="0x5c" variants="A5XX-"/>
 	<!-- A5XX Enable yield in RB only -->
 	<value name="CP_YIELD_ENABLE" value="0x1c" variants="A5XX"/>
+	<doc>
+		Enables IB2 skipping.  If both GLOBAL and LOCAL are 1 and
+		nothing is left in the visibility stream, then
+		CP_INDIRECT_BUFFER will be skipped, and draws will early return
+		from their IB.
+	</doc>
 	<value name="CP_SKIP_IB2_ENABLE_GLOBAL" value="0x1d" variants="A5XX-"/>
 	<value name="CP_SKIP_IB2_ENABLE_LOCAL" value="0x23" variants="A5XX-"/>
 	<value name="CP_SET_SUBDRAW_SIZE" value="0x35" variants="A5XX-"/>