From 05d11f8bd73a44d5dd5b718ae86790daca2fdfa5 Mon Sep 17 00:00:00 2001
From: kinho <109323159+KinhoLeung@users.noreply.github.com>
Date: Mon, 24 Nov 2025 23:19:49 +0800
Subject: [PATCH] fix:Report the full buffer length to the UAC stack by setting
 bytes_read in usb_uac_device_input_cb(), so the host correctly detects
 received audio data instead of seeing zero bytes.

---
 .../i2s/i2s_advance/i2s_usb/main/i2s_usb_example_main.c      | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/examples/peripherals/i2s/i2s_advance/i2s_usb/main/i2s_usb_example_main.c b/examples/peripherals/i2s/i2s_advance/i2s_usb/main/i2s_usb_example_main.c
index bf66f0d52b4a..2f1e8c290974 100644
--- a/examples/peripherals/i2s/i2s_advance/i2s_usb/main/i2s_usb_example_main.c
+++ b/examples/peripherals/i2s/i2s_advance/i2s_usb/main/i2s_usb_example_main.c
@@ -236,6 +236,11 @@ static esp_err_t usb_uac_device_input_cb(uint8_t *buf, size_t len, size_t *bytes
         return ESP_FAIL;
     }
 
+    /* Report full-length data for UAC */
+    if (bytes_read) {
+        *bytes_read = len;
+    }
+
     return ESP_OK;
 }