When running a2dp_sink_demo, an error occurs after pausing and then resuming the music.

[huenrong]

Describe the bug

When running a2dp_sink_demo on RK3308, an error occurs after pausing and then resuming the music.
Error message: Error storing samples in SBC ring buffer!!!

To Reproduce

Steps to reproduce the behavior:

1. Run example 'a2dp_sink_demo' on RK3308
2. Connect to device 'iPhone17'
3. Playing music on an iPhone 17, the RK3308 can output sound
4. Paused on the iPhone 17, the RK3308 outputs no sound
5. Waiting for the RK3308 terminal to output "A2DP Sink : Stream paused"
6. Resumes on the iPhone 17, the RK3308 terminal displays an error message. Error storing samples in SBC ring buffer!!!

Expected behavior

Playback can be resumed normally.

HCI Packet Logs

hci_dump_a2dp_sink_demo.tar.gz

Additional context

My investigation revealed that adding a call to the snd_pcm_prepare() function within the alsa_stop_stream() function in the btstack_audio_alsa.c file resolved the issue.

The modified function is as follows

static void alsa_stop_stream(void) {
    snd_pcm_drop(pcm_handle);
    snd_pcm_prepare(pcm_handle); // add
}

[mringwal]

Hi.

Thanks for reporting and the fix. I was able to reproduce this in an Ubuntu 24.04 VM with my iPhone 12.

After adding 'snd_pcm_prepare()' in alsa_stop_stream() and resuming playback, I got the error "Write error: Broken pipe"

You could also try the PortAudio version, which should be detected by the CMake file.

[huenrong]

I've seen the same error ("Write error: Broken pipe"), but I forgot whether I added snd_pcm_prepare() at the time. Now I don't have this error.