Merge pull request #281 from espressif/fix/uac_ringbuf

fix(uac): Wait until requested bytes are read

Author: tore-espressif

host/class/uac/usb_host_uac/CHANGELOG.md

@@ -1,36 +1,45 @@
 # Changelog for USB Host UAC
 
-## 1.3.1
+All notable changes to this component will be documented in this file.
 
-1. Added support for ESP32-H4
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## 1.3.0
+## [1.3.2] - 2025-10-21
 
-1. Added Linux target build for the UAC component, host tests (https://github.com/espressif/esp-usb/issues/143)
+### Changed
 
-## 1.2.0 2024-09-27
+- uac_host_device_read() now waits for the full timeout duration until the required amount of data is read, preventing premature returns with partial data (https://github.com/espressif/esp-usb/issues/248)
 
-### Breaking Changes:
+## [1.3.1] - 2025-09-24
+
+- Added support for ESP32-H4
+
+## [1.3.0] - 2025-03-28
 
-1. Changed the parameter type of `uac_host_device_set_volume_db` from uint32_t to int16_t
+- Added Linux target build for the UAC component, host tests (https://github.com/espressif/esp-usb/issues/143)
+
+## [1.2.0] - 2024-10-10
+
+### Breaking Changes:
 
+- Changed the parameter type of `uac_host_device_set_volume_db` from uint32_t to int16_t
 
 ### Improvements:
 
-1. Support get current volume and mute status
+- Support get current volume and mute status
 
 ### Bugfixes:
 
-1. Fixed incorrect volume conversion. Using actual device volume range.
-2. Fixed concurrency issues when suspend/stop during read/write
+- Fixed incorrect volume conversion. Using actual device volume range.
+- Fixed concurrency issues when suspend/stop during read/write
 
-## 1.1.0
+## [1.1.0] - 2024-07-08
 
 ### Improvements
 
 - Added add `uac_host_device_open_with_vid_pid` to open connected audio devices with known VID and PID
 - Print component version message `uac-host: Install Succeed, Version: 1.1.0` in `uac_host_install` function
 
-## 1.0.0
+## [1.0.0] - 2024-05-23
 
 - Initial version

host/class/uac/usb_host_uac/README.md

@@ -1,6 +1,8 @@
 # USB Host UAC Driver
 
 [![Component Registry](https://components.espressif.com/components/espressif/usb_host_uac/badge.svg)](https://components.espressif.com/components/espressif/usb_host_uac)
+![maintenance-status](https://img.shields.io/badge/maintenance-actively--developed-brightgreen.svg)
+![changelog](https://img.shields.io/badge/Keep_a_Changelog-blue?logo=keepachangelog&logoColor=E05735)
 
 This directory contains an implementation of a USB UAC Driver implemented on top of the [USB Host Library](https://docs.espressif.com/projects/esp-idf/en/latest/esp32s2/api-reference/peripherals/usb_host.html).
 

host/class/uac/usb_host_uac/idf_component.yml

@@ -1,5 +1,5 @@
 ## IDF Component Manager Manifest File
-version: "1.3.1"
+version: "1.3.2"
 description: USB Host UAC driver
 url: https://github.com/espressif/esp-usb/tree/master/host/class/uac/usb_host_uac
 dependencies:

host/class/uac/usb_host_uac/uac_host.c

@@ -276,25 +276,58 @@ static esp_err_t _ring_buffer_push(RingbufHandle_t ringbuf_hdl, uint8_t *buf, si
 static esp_err_t _ring_buffer_pop(RingbufHandle_t ringbuf_hdl, uint8_t *buf, size_t req_bytes, size_t *read_bytes, TickType_t ticks_to_wait)
 {
     assert(ringbuf_hdl && buf && read_bytes);
-    uint8_t *buf_rcv = xRingbufferReceiveUpTo(ringbuf_hdl, read_bytes, ticks_to_wait, req_bytes);
-
-    if (!buf_rcv) {
-        return ESP_FAIL;
+    /* Read up to req_bytes, blocking up to ticks_to_wait in total.
+     * xRingbufferReceiveUpTo may return fewer bytes than requested even if
+     * the caller asked for more, so loop until we've collected the full
+     * amount or the timeout expires. If nothing is read before timeout,
+     * return ESP_ERR_TIMEOUT. If some bytes were read and timeout expires, return
+     * ESP_OK with the actual number of bytes read.
+     */
+    if (req_bytes == 0) {
+        *read_bytes = 0;
+        return ESP_OK;
     }
 
-    memcpy(buf, buf_rcv, *read_bytes);
-    vRingbufferReturnItem(ringbuf_hdl, (void *)(buf_rcv));
+    size_t total_read = 0;
+    TickType_t start_ticks = xTaskGetTickCount();
 
-    size_t read_bytes2 = 0;
-    if (*read_bytes < req_bytes) {
-        buf_rcv = xRingbufferReceiveUpTo(ringbuf_hdl, &read_bytes2, 0, req_bytes - *read_bytes);
-        if (buf_rcv) {
-            memcpy(buf + *read_bytes, buf_rcv, read_bytes2);
-            *read_bytes += read_bytes2;
-            vRingbufferReturnItem(ringbuf_hdl, (void *)(buf_rcv));
+    while (total_read < req_bytes) {
+        size_t chunk_read = 0;
+        size_t want = req_bytes - total_read;
+
+        /* compute remaining ticks to wait */
+        TickType_t elapsed = xTaskGetTickCount() - start_ticks;
+        TickType_t remain = 0;
+        if (ticks_to_wait == portMAX_DELAY) {
+            remain = portMAX_DELAY;
+        } else if (elapsed >= ticks_to_wait) {
+            remain = 0;
+        } else {
+            remain = ticks_to_wait - elapsed;
+        }
+
+        uint8_t *buf_rcv = xRingbufferReceiveUpTo(ringbuf_hdl, &chunk_read, remain, want);
+
+        if (!buf_rcv) {
+            /* nothing available within remaining timeout */
+            break;
+        }
+
+        /* copy received chunk */
+        memcpy(buf + total_read, buf_rcv, chunk_read);
+        vRingbufferReturnItem(ringbuf_hdl, (void *)buf_rcv);
+        total_read += chunk_read;
+        if (chunk_read == 0) {
+            /* defensive: in case the chunk is zero length */
+            break;
         }
     }
 
+    if (total_read == 0) {
+        return ESP_ERR_TIMEOUT;
+    }
+
+    *read_bytes = total_read;
     return ESP_OK;
 }
 
@@ -2385,11 +2418,7 @@ esp_err_t uac_host_device_read(uac_host_device_handle_t uac_dev_handle, uint8_t
     }
     uac_host_interface_unlock(iface);
 
-    size_t data_len = _ring_buffer_get_len(iface->ringbuf);
-    if (data_len > size) {
-        data_len = size;
-    }
-    esp_err_t ret = _ring_buffer_pop(iface->ringbuf, data, data_len, (size_t *)bytes_read, timeout);
+    esp_err_t ret = _ring_buffer_pop(iface->ringbuf, data, size, (size_t *)bytes_read, timeout);
 
     if (ESP_OK != ret) {
         ESP_LOGD(TAG, "RX Ringbuffer read failed");