Re: [PATCH] ASoC: SOF: Fix snd_sof_ipc_stream_posn()

[Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>]

>> We're passing "&posn" instead of "posn" so it ends up corrupting
>> memory instead of doing something useful.
> [...]
>>   	/* send IPC to the DSP */
>>   	err = sof_ipc_tx_message(sdev->ipc,
>> -				 stream.hdr.cmd, &stream, sizeof(stream), &posn,
>> +				 stream.hdr.cmd, &stream, sizeof(stream), posn,
>>   				 sizeof(*posn));
> 
> ack, thanks, this is clearly wrong. This function is not used by current
> platforms, so the bug has gone unnnoticed. Most platforms either rely on
> direct MMIO queries of the DSP position, or the periodic position updates
> DSPs send after each ALSA period. This function for host to query DSP
> position via IPC is thus not used, although it's part of the generic audio
> DSP IPC interface.
> 
> For the SOF folks in CC, I wonder should we keep this function at all?
> 
> Anyways, that's probably a longer discussion, so while it's there,
> the code should be correct, so for the patch:
> Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

I checked all the way to 5.2 and it was never used, so indeed wondering 
what the purpose of this function was.