From d9ec32d40f9aeb49613af35f6e7f645ee6b2239f Mon Sep 17 00:00:00 2001
From: sladro <sladro@163.com>
Date: Tue, 6 Jan 2026 14:57:18 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AEbug?=
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---
 src/utils/dma_alloc.cpp | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/utils/dma_alloc.cpp b/src/utils/dma_alloc.cpp
index 042b7dd..ba1e908 100644
--- a/src/utils/dma_alloc.cpp
+++ b/src/utils/dma_alloc.cpp
@@ -164,14 +164,26 @@ DmaBufferPtr DmaAlloc(size_t alloc_size) {
         return DmaBufferPtr(reused, [](DmaBuffer* b) { Pool().Put(b); });
     }
 
-    // Try different dma_heap devices - prefer CMA for RGA compatibility (<4GB)
+    // Try different dma_heap devices.
+    // Notes:
+    // - Some RGA drivers cannot map buffers whose physical address is >4GB; prefer DMA32 heaps.
+    // - CMA heaps are also <4GB friendly but can be small/fragmented under multi-stream load.
     const char* heap_paths[] = {
+        // Prefer CMA first when available.
         "/dev/dma_heap/cma",
-        "/dev/dma_heap/cma-uncached", 
+        "/dev/dma_heap/cma-uncached",
         "/dev/dma_heap/linux,cma",
-        "/dev/dma_heap/reserved",
+
+        // Then prefer DMA32 heaps to keep allocations under 4GB.
+        "/dev/dma_heap/system-dma32",
+        "/dev/dma_heap/system-uncached-dma32",
+
+        // Generic system heaps (may allocate >4GB on high-mem systems).
         "/dev/dma_heap/system-uncached",
         "/dev/dma_heap/system",
+
+        // Last resort.
+        "/dev/dma_heap/reserved",
         nullptr
     };