diff --git a/src/freedreno/registers/adreno/a6xx.xml b/src/freedreno/registers/adreno/a6xx.xml
index 0a2fecca4d1..e0c481d1039 100644
--- a/src/freedreno/registers/adreno/a6xx.xml
+++ b/src/freedreno/registers/adreno/a6xx.xml
@@ -2842,7 +2842,11 @@ to upconvert to 32b float internally?
 		</reg32>
 	</array>
 	<!-- 0x891b-0x8926 invalid -->
-	<reg64 offset="0x8927" name="RB_SAMPLE_COUNT_ADDR" type="waddress" align="16" usage="cmd" variants="A6XX"/>
+	<doc>
+		RB_SAMPLE_COUNT_ADDR register is used up to (and including) a730. After that
+		the address is specified through CP_EVENT_WRITE7::WRITE_SAMPLE_COUNT.
+	</doc>
+	<reg64 offset="0x8927" name="RB_SAMPLE_COUNT_ADDR" type="waddress" align="16" usage="cmd"/>
 	<!-- 0x8929-0x89ff invalid -->
 
 	<!-- TODO: there are some registers in the 0x8a00-0x8bff range -->