[alsa-devel] [PATCH v4 08/13] ASoC: Add SoundWire stream programming interface

[Pierre-Louis Bossart]

On 4/21/18 10:58 AM, Vinod Koul wrote:
> On Sat, Apr 21, 2018 at 06:59:49AM -0700, Pierre-Louis Bossart wrote:
>>
>>> +/**
>>> + * snd_soc_dai_set_sdw_stream() - Configures a DAI for SDW stream operation
>>> + * @dai: DAI
>>> + * @stream: STREAM
>>> + * @direction: Stream direction(Playback/Capture)
>>> + * SoundWire subsystem doesn't have a notion of direction and we reuse
>>> + * the ASoC stream direction to configure sink/source ports.
>>> + * Playback maps to source on the TX and sink on Rx. Vice-versa for Capture.
>>
>> this is just confusing...
>>
>> This should be something like
>> "use Playback for source ports and Capture for sink ports".
> 
> Source port on ...? This is also confusing to me!
> 
> For playback there are two ports, one on transmitter aka
> TX and one on receiver aka RX. For Tx we use source port, and Rx uses sink
> ports. I should probably add port to make people really figure out we are
> talking about ports!
> 
> So:
> 
> Playback maps to source port on the TX and sink port on Rx. Vice-versa for Capture.
> 
> Do you agree to above statement?

No. Source port and TX are redundant definitions, and your wording isn't 
clear: is the PLAYBACK/CAPTURE qualifier for the stream or the DAI used 
by the stream?