From 834bd96111553dd5c8ec599e29f3585c10a1e673 Mon Sep 17 00:00:00 2001
From: Daniel Maddern <daniel.maddern@illuvium.io>
Date: Wed, 19 Aug 2026 22:27:16 +0700
Subject: [PATCH] Trace x shape at deepstack layers

---
 src/h3_blackwell_runtime/qwen3vl_vision.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/h3_blackwell_runtime/qwen3vl_vision.py b/src/h3_blackwell_runtime/qwen3vl_vision.py
index dbf0dbc..8e584a0 100644
--- a/src/h3_blackwell_runtime/qwen3vl_vision.py
+++ b/src/h3_blackwell_runtime/qwen3vl_vision.py
@@ -698,8 +698,8 @@ class Qwen3VL32BVision(nn.Module):
         deepstack_features = []
         for layer_num, block in enumerate(self.blocks):
             x = block(x, cu_seqlens=cu_seqlens, position_embeddings=position_embeddings)
-            if layer_num == 0:
-                print(f"[vision] after block 0: x.shape={tuple(x.shape)}, grid_thw={grid_thw.tolist()}")
+            if layer_num in (0, 8, 16, 24) or layer_num == self.depth - 1:
+                print(f"[vision] after block {layer_num}: x.shape={tuple(x.shape)}")
             if layer_num in self.deepstack_visual_indexes:
                 # x should be [N_patches, C]; if not, re-flatten.
                 if x.ndim != 2: