[Bugfix] Profile maximum DeepSeek V4.1 vision features (#57898)

Signed-off-by: ahmed xijiaat <52128022+xijiaat@users.noreply.github.com>
Co-authored-by: OpenAI Codex <noreply@openai.com>
Co-authored-by: Isotr0py <Isotr0py@outlook.com>

vllm/models/deepseek_v41/common/mm_preprocess.py

@@ -275,15 +275,28 @@ class DeepseekV4VLProcessingInfo(BaseProcessingInfo):
         hf_config = self.get_hf_config()
         patch_size = hf_config.vision_patch_size
         downsample_ratio = hf_config.vision_downsample_ratio
-        # A square maximizes the ViT patch count (area) within the token
-        # budget; solve the budget-derived size directly to keep the dummy
-        # image small.
         budget = hf_config.vision_max_n_token
-        side = budget * patch_size * downsample_ratio
-        best_h, best_w = solve_resize_ratio(
-            side, side, patch_size, downsample_ratio, budget
-        )
-        return ImageSize(width=best_w, height=best_h)
+        max_wh_ratio = hf_config.vision_max_wh_ratio
+        best_h = best_w = 0
+        # Each LLM row costs an extra newline token. Maximize the ViT grid,
+        # including the patch rounding after the optional aspect-ratio clamp.
+        for n_llm_h in range(1, (budget - 2) // 2 + 1):
+            n_vit_h = n_llm_h * downsample_ratio
+            n_vit_w = ((budget - 2) // n_llm_h - 1) * downsample_ratio
+            if max_wh_ratio is not None:
+                n_vit_w = min(n_vit_w, math.ceil(n_vit_h * max_wh_ratio))
+            if n_vit_h * n_vit_w > best_h * best_w:
+                best_h, best_w = n_vit_h, n_vit_w
+        if best_h == 0:
+            raise ValueError(
+                "Image token budget and aspect ratio allow no image patches"
+            )
+        height, width = best_h * patch_size, best_w * patch_size
+        # Avoid the min-pixels upscaler perturbing the selected aspect ratio.
+        scale = 1
+        while height * width * scale * scale < hf_config.vision_min_pixels:
+            scale *= 2
+        return ImageSize(width=width * scale, height=height * scale)
 
 
 class DeepseekV4VLDummyInputsBuilder(