USB Audio Hal: Fix CTS timestamp handling am: 61583424ff
Original change: https://googleplex-android-review.googlesource.com/c/platform/hardware/libhardware/+/15190378
Change-Id: Ic90d8c34a120a2a98d576d583eadcc2392da844b
diff --git a/modules/usbaudio/audio_hal.c b/modules/usbaudio/audio_hal.c
index cc9e4f7..39c0fb5 100644
--- a/modules/usbaudio/audio_hal.c
+++ b/modules/usbaudio/audio_hal.c
@@ -1652,6 +1652,15 @@
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 @@
} 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) {