Re: [PATCH linux-next v2 8/9] ASoC: rsnd: ssi: Request dedicated dma channels for busif0 to 7

[Jiada Wang]

Hi Morimoto-san


On 2018/10/04 10:12, Kuninori Morimoto wrote:
> Hi Jiada
>
> Thank you for your patch
>
> > Currently ssi driver only request dma channel for SSI_0,
> > which is used to transfer data to/from busif0.
> >
> > But in GEN3 busif1 to busif7 also maybe used, dedicated dma channels
> > are requested for data transfer through these busif.
> >
> > Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx>
> > ---
> (snip)
> > +	if (rsnd_ssi_use_busif(io)) {
> > +		if (is_play)
> > +			snprintf(name, SSI_DMA_NAME_SIZE, "rxu");
> > +		else
> > +			snprintf(name, SSI_DMA_NAME_SIZE, "txu");
> > +
> > +		if (rsnd_is_gen3(priv)) {
> > +			/*
> > +			 * Gen3 supports to use all available BUSIF
> > +			 */
> > +			int busif = rsnd_ssi_get_busif(io);
> > +
> > +			snprintf(name, SSI_DMA_NAME_SIZE, "%s%d", name, busif);
> > +		}
> I think unspecified GenX is better idea.
> For example, we might want to have same setting on Gen2 in the future.
> (and this is not Gen3 HW specific feature
>   But yes, we have SW side reason)
>
> How about like this ?
> We can keep compatibility, and both Gen2/Gen3 can use it.
>
> 	if (rsnd_ssi_use_busif(io)) {
> 		/*
> 		 * 1) try to find txu%d/rxu%d first
> 		 * 2) If can't find it, try to find old txu/rxu
> 		 */
> 	}
I think this is a good idea, by doing so,
in case GEN2 DT also starts to support different BUSIF,
then no driver side change is required.

I will update accordingly in next version

Thanks,
Jiada