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

Kuninori Morimoto kuninori.morimoto.gx at renesas.com
Thu Oct 4 03:12:13 CEST 2018


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 at mentor.com>
> ---
(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
		 */
	}


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