IPC_IA_FREE_STREAM   62 sound/soc/intel/atom/sst-mfld-dsp.h #define IPC_IA_FREE_STREAM 0x21 /* Free the stream ID */
IPC_IA_FREE_STREAM   50 sound/soc/intel/baytrail/sst-baytrail-ipc.c #define IPC_IA_FREE_STREAM	0x21