Cannot pause for example program 'pipeline_hfp_stream_exammple'

[wangqg]

Two pipelines, pipeline in and pipeline out are declared in the example. But the pipleline cannot be paused.
I got log when pause pipeline out like:
W (177498) BT_HCI: hcif conn complete: hdl 0x81, st 0x0
W (180698) BT_HCI: hcif disc complete: hdl 0x81, rsn 0x13

But I can get log when pause pipeline in like:
I (5678) AUDIO_ELEMENT: [i2s_writer] AEL_MSG_CMD_PAUSE

Can anybody help? Many thinks !