Re: [RFC PATCH 01/16] Documentation: driver: add SoundWire BRA description

[Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>]

On Mon, Dec 18, 2023 at 01:58:47PM +0100, Pierre-Louis Bossart wrote:
> > why not have a single API that does both? First check if it is supported
> > and then allocate buffers and do the transfer.. What are the advantages
> > of using this two step process
> 
> Symmetry is the only thing that comes to my mind. Open - close and send
> - wait are natural matches, aren't they?
> 
> We do need a wait(), so bundling open() and send() would be odd.
> 

I agree send->wait->close would be odd, But you just bundle close
into wait. So the API becomes just send->wait, which seems pretty
logical.

> But you have a point that the open() is not generic in that it also
> prepares the DMA buffers for transmission. Maybe it's more natural to
> follow the traditional open(), hw_params(), hw_free, close() from ALSA.

I think this just makes it worse, you are now adding even more
calls. The problem I see here is that, open and close (at least to
me) strongly implies that you can do multiple operations between
them and unless I have misunderstood something here you can't.

Thanks,
Charles