From cee65540d8bdcb0f2887004cdc09ee22e496727a Mon Sep 17 00:00:00 2001
From: sladro <sladro@163.com>
Date: Fri, 26 Dec 2025 16:17:25 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BD=BF=E7=94=A8=20DMA-BUF=20=E5=88=86?=
 =?UTF-8?q?=E9=85=8D=E5=86=85=E5=AD=98=EF=BC=8C=E4=BF=AE=E5=A4=8D=E5=8A=9F?=
 =?UTF-8?q?=E8=83=BDbug?=
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---
 src/utils/dma_alloc.cpp | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/utils/dma_alloc.cpp b/src/utils/dma_alloc.cpp
index 1523b1a..109c285 100644
--- a/src/utils/dma_alloc.cpp
+++ b/src/utils/dma_alloc.cpp
@@ -80,27 +80,43 @@ DmaBuffer& DmaBuffer::operator=(DmaBuffer&& other) noexcept {
 
 DmaBufferPtr DmaAlloc(size_t alloc_size) {
 #if defined(__linux__)
-    // Try different dma_heap devices
+    // Try different dma_heap devices - prefer CMA for RGA compatibility (<4GB)
     const char* heap_paths[] = {
+        "/dev/dma_heap/cma",
+        "/dev/dma_heap/cma-uncached", 
+        "/dev/dma_heap/linux,cma",
+        "/dev/dma_heap/reserved",
         "/dev/dma_heap/system-uncached",
         "/dev/dma_heap/system",
-        "/dev/dma_heap/cma",
         nullptr
     };
 
     int heap_fd = -1;
+    const char* used_heap = nullptr;
     for (int i = 0; heap_paths[i] != nullptr; ++i) {
         heap_fd = open(heap_paths[i], O_RDWR | O_CLOEXEC);
         if (heap_fd >= 0) {
+            used_heap = heap_paths[i];
             break;
         }
     }
 
     if (heap_fd < 0) {
         std::cerr << "[DmaAlloc] failed to open dma_heap device: " << strerror(errno) << "\n";
+        std::cerr << "[DmaAlloc] tried: ";
+        for (int i = 0; heap_paths[i] != nullptr; ++i) {
+            std::cerr << heap_paths[i] << " ";
+        }
+        std::cerr << "\n";
         return nullptr;
     }
 
+    static bool first_alloc = true;
+    if (first_alloc) {
+        std::cout << "[DmaAlloc] using heap: " << used_heap << "\n";
+        first_alloc = false;
+    }
+
     dma_heap_allocation_data alloc_data{};
     alloc_data.len = alloc_size;
     alloc_data.fd_flags = O_RDWR | O_CLOEXEC;