audio: preserve descriptor sample-rate entries

Retain every valid discrete rate in descriptor order, including duplicate public tuples. Alternate settings remain independently selectable without disruptive validation or deduplication during enumeration.

Signed-off-by: HiFiPHile <[email protected]>

2 files changed, 20 insertions, 28 deletions

diff --git a/src/class/audio/audio_host.c b/src/class/audio/audio_host.c
index 8caecf3d2..a28cad156 100644
--- a/src/class/audio/audio_host.c
+++ b/src/class/audio/audio_host.c
@@ -994,29 +994,6 @@ static const uint8_t *audioh_parse_as(audioh_interface_t *p_audio, const tusb_de
                  itf_num, alt, ep->ep_size);
       continue;
     }
-    // Skip duplicate configurations already retained from another AS or from
-    // an earlier frequency entry in this descriptor.
-    bool duplicate = false;
-    for (uint8_t as_idx = 0; as_idx < stream->as_count && !duplicate; as_idx++) {
-      const audioh_as_config_t *existing = &stream->as[as_idx];
-      if (existing->format == (uint8_t)format && existing->channels == num_channels) {
-        for (uint8_t rate_idx = 0; rate_idx < existing->sample_rate_count; rate_idx++) {
-          if (existing->sample_rate[rate_idx] == sample_rate) {
-            duplicate = true;
-            break;
-          }
-        }
-      }
-    }
-    for (uint8_t rate_idx = 0; rate_idx < as_config.sample_rate_count && !duplicate; rate_idx++) {
-      if (as_config.sample_rate[rate_idx] == sample_rate) {
-        duplicate = true;
-      }
-    }
-    if (duplicate) {
-      continue;
-    }
-
     as_config.sample_rate[as_config.sample_rate_count++] = sample_rate;
   }
 
diff --git a/test/unit-test/test/host/audio/test_audio_host.c b/test/unit-test/test/host/audio/test_audio_host.c
index 62119f7be..0d7569090 100644
--- a/test/unit-test/test/host/audio/test_audio_host.c
+++ b/test/unit-test/test/host/audio/test_audio_host.c
@@ -396,7 +396,7 @@ static const uint8_t playback_with_two_frequencies[] = {
   TEST_UAC1_AS_ALT0,
   TEST_UAC1_AS_INTERFACE(1, 1),
   TEST_UAC1_AS_GENERAL(PLAYBACK_INPUT_TERM),
-  TEST_UAC1_FORMAT(2, 2, 16, 44100, 48000),
+  TEST_UAC1_FORMAT(2, 2, 16, 44100, 44100, 48000),
   TEST_UAC1_DATA_EP(0x01, TUSB_ISO_EP_ATT_ADAPTIVE, 384, 2),
   TEST_UAC1_CS_DATA_EP,
 };
@@ -479,7 +479,7 @@ static const uint8_t playback_with_two_alternates[] = {
   TEST_UAC1_CS_DATA_EP,
   TEST_UAC1_AS_INTERFACE(2, 1),
   TEST_UAC1_AS_GENERAL(PLAYBACK_INPUT_TERM),
-  TEST_UAC1_FORMAT(2, 2, 16, 96000),
+  TEST_UAC1_FORMAT(2, 2, 16, 48000, 96000),
   TEST_UAC1_DATA_EP(0x02, TUSB_ISO_EP_ATT_ADAPTIVE, 384, 1),
   TEST_UAC1_CS_DATA_EP,
 };
@@ -889,19 +889,34 @@ void test_audio_host_parses_discrete_frequencies_with_interval_greater_than_one(
   tuh_audio_stream_config_t config;
   mount_descriptors(playback_with_two_frequencies, sizeof(playback_with_two_frequencies));
 
-  TEST_ASSERT_EQUAL_UINT8(2, tuh_audio_config_count(0, 0));
+  TEST_ASSERT_EQUAL_UINT8(3, tuh_audio_config_count(0, 0));
   TEST_ASSERT_TRUE(tuh_audio_config_get(0, 0, 0, &config));
   TEST_ASSERT_EQUAL_UINT32(44100, config.sample_rate);
   TEST_ASSERT_TRUE(tuh_audio_config_get(0, 0, 1, &config));
+  TEST_ASSERT_EQUAL_UINT32(44100, config.sample_rate);
+  TEST_ASSERT_TRUE(tuh_audio_config_get(0, 0, 2, &config));
   TEST_ASSERT_EQUAL_UINT32(48000, config.sample_rate);
 
-  // Both public configurations share one AS mapping but retain their own rate.
-  TEST_ASSERT_TRUE(tuh_audio_configure(0, 0, 1));
+  // All public configurations share one AS mapping and preserve descriptor order.
+  TEST_ASSERT_TRUE(tuh_audio_configure(0, 0, 2));
   TEST_ASSERT_TRUE(tuh_audio_start(0, 0));
   complete_interface_set(XFER_RESULT_SUCCESS);
   TEST_ASSERT_EQUAL_HEX8_ARRAY(((uint8_t[]){U24_TO_U8S_LE(48000)}), control_buffer, 3);
 }
 
+void test_audio_host_retains_same_rate_in_different_alternate_settings(void) {
+  tuh_audio_stream_config_t config;
+  mount_descriptors(playback_with_two_alternates, sizeof(playback_with_two_alternates));
+
+  TEST_ASSERT_EQUAL_UINT8(3, tuh_audio_config_count(0, 0));
+  TEST_ASSERT_TRUE(tuh_audio_config_get(0, 0, 0, &config));
+  TEST_ASSERT_EQUAL_UINT32(48000, config.sample_rate);
+  TEST_ASSERT_TRUE(tuh_audio_config_get(0, 0, 1, &config));
+  TEST_ASSERT_EQUAL_UINT32(48000, config.sample_rate);
+  TEST_ASSERT_TRUE(tuh_audio_config_get(0, 0, 2, &config));
+  TEST_ASSERT_EQUAL_UINT32(96000, config.sample_rate);
+}
+
 void test_audio_host_keeps_supported_stream_when_other_as_format_is_unsupported(void) {
   open_descriptors(playback_with_unsupported_capture, sizeof(playback_with_unsupported_capture));