From e342d8151afe9a7a51c61b3c3f479f64c8eb54b0 Mon Sep 17 00:00:00 2001
From: sexenteen <130895816+sexenteen@users.noreply.github.com>
Date: Mon, 26 Oct 2026 01:27:42 +0800
Subject: [PATCH] fix[serial]: keep rx indicate callback while the port is
 still shared

---
 components/drivers/serial/dev_serial.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/components/drivers/serial/dev_serial.c b/components/drivers/serial/dev_serial.c
index 483f59f1e2b0..2d1f4561d902 100644
--- a/components/drivers/serial/dev_serial.c
+++ b/components/drivers/serial/dev_serial.c
@@ -116,9 +116,17 @@ static int serial_fops_close(struct dfs_file *fd)
 
     device = (rt_device_t)fd->vnode->data;
 
-    rt_device_set_rx_indicate(device, RT_NULL);
+    /* close this file descriptor, but only drop the rx indication callback when
+     * the device is really released. The callback wakes readers (see
+     * serial_fops_rx_ind), so clearing it while another user still holds the
+     * device would make that user stop receiving input. */
     rt_device_close(device);
 
+    if (device->ref_count == 0)
+    {
+        rt_device_set_rx_indicate(device, RT_NULL);
+    }
+
     return 0;
 }