From 9c18773e65236069b2cc84369b8d2130d418e97a Mon Sep 17 00:00:00 2001
From: sladro <sladro@163.com>
Date: Mon, 5 Jan 2026 18:56:10 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E5=A4=8D=E8=8A=B1=E5=B1=8F3?=
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---
 plugins/preprocess/preprocess_node.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/plugins/preprocess/preprocess_node.cpp b/plugins/preprocess/preprocess_node.cpp
index 1e91fd4..3b99166 100644
--- a/plugins/preprocess/preprocess_node.cpp
+++ b/plugins/preprocess/preprocess_node.cpp
@@ -360,10 +360,14 @@ private:
                 std::cerr << "[preprocess] DMA alloc for src failed\n";
                 return false;
             }
+            // CPU writes to a DMA-BUF must be flushed before RGA reads it.
+            DmaSyncStartFd(src_dma_buf->fd);
             if (!CopyToStridedBuffer(*frame, src_dma_buf->data(), src_dma_buf->size, src_wstride, src_hstride)) {
+                DmaSyncEndFd(src_dma_buf->fd);
                 std::cerr << "[preprocess] copy src to DMA failed\n";
                 return false;
             }
+            DmaSyncEndFd(src_dma_buf->fd);
             src_buf = wrapbuffer_fd_t(src_dma_buf->fd, frame->width, frame->height,
                                       src_wstride, src_hstride, src_fmt_rga);
         } else {