From 61583424ff6f0135ebffda9507b085dc6839d430 Mon Sep 17 00:00:00 2001 From: Andy Hung Date: Fri, 2 Jul 2021 16:13:11 -0700 Subject: [PATCH] USB Audio Hal: Fix CTS timestamp handling Bug: 192702566 Test: atest AudioRecordTest#testTimestamp Change-Id: I3f045b309c8a95ecbe042fd9222e627cac2cb1c9 --- modules/usbaudio/audio_hal.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/modules/usbaudio/audio_hal.c b/modules/usbaudio/audio_hal.c index cc9e4f7c..39c0fb5c 100644 --- a/modules/usbaudio/audio_hal.c +++ b/modules/usbaudio/audio_hal.c @@ -1652,6 +1652,15 @@ static int adev_create_audio_patch(struct audio_hw_device *dev, stream_standby_l(alsa_devices, out == NULL ? &in->standby : &out->standby); device_unlock(adev); + // Timestamps: + // Audio timestamps assume continuous PCM frame counts which are maintained + // with the device proxy.transferred variable. Technically it would be better + // associated with in or out stream, not the device; here we save and restore + // using the first alsa device as a simplification. + uint64_t saved_transferred_frames = 0; + struct alsa_device_info *device_info = stream_get_first_alsa_device(alsa_devices); + if (device_info != NULL) saved_transferred_frames = device_info->proxy.transferred; + int ret = stream_set_new_devices(config, alsa_devices, num_configs, cards, devices, direction); if (ret != 0) { @@ -1661,6 +1670,13 @@ static int adev_create_audio_patch(struct audio_hw_device *dev, } else { *patch_handle = *handle; } + + // Timestamps: Restore transferred frames. + if (saved_transferred_frames != 0) { + device_info = stream_get_first_alsa_device(alsa_devices); + if (device_info != NULL) device_info->proxy.transferred = saved_transferred_frames; + } + if (!wasStandby) { device_lock(adev); if (in != NULL) {