diff --git a/src/asahi/lib/cmdbuf.xml b/src/asahi/lib/cmdbuf.xml
index 8a38ca58987..ad39fcf5c6b 100644
--- a/src/asahi/lib/cmdbuf.xml
+++ b/src/asahi/lib/cmdbuf.xml
@@ -314,6 +314,9 @@
     <!-- If layout is linear, stride has the minus 1 encoded -->
     <field name="Depth (linear)" size="11" start="128" type="uint" modifier="minus(1)" default="1"/>
     <field name="Layer stride (linear)" size="27" start="139" type="uint" modifier="shr(7)"/>
+
+    <!-- Buffer texture size -->
+    <field name="Software-defined" size="64" start="128" type="hex"/>
   </struct>
 
   <enum name="Wrap">
diff --git a/src/gallium/drivers/asahi/agx_state.c b/src/gallium/drivers/asahi/agx_state.c
index 0e3b4b68d36..4e87783f434 100644
--- a/src/gallium/drivers/asahi/agx_state.c
+++ b/src/gallium/drivers/asahi/agx_state.c
@@ -666,10 +666,8 @@ agx_pack_texture(void *out, struct agx_resource *rsrc,
          cfg.height = DIV_ROUND_UP(size_el, cfg.width);
          cfg.first_level = cfg.last_level = 0;
 
-         /* Stash the actual size in an unused part of the texture descriptor,
-          * which we'll read later to implement txs.
-          */
-         cfg.acceleration_buffer = (size_el << 4);
+         /* Stash the actual size in the software-defined section for txs */
+         cfg.software_defined = size_el;
       } else {
          cfg.width = rsrc->base.width0;
          cfg.height = rsrc->base.height0;