Re: [PATCH 2/2] ASoC: fsl_asrc: Add support for imx8qm

[Nicolin Chen <nicoleotsuka@gmail.com>]

On Tue, Oct 29, 2019 at 05:17:09PM +0800, Shengjiu Wang wrote:
> There are two asrc module in imx8qm, each module has different
> clock configuration, and the DMA type is EDMA.
> 
> So in this patch, we define the new clocks, refine the clock map,
> and include struct fsl_asrc_soc_data for different soc usage.
> 
> The EDMA channel is fixed with each dma request, one dma request
> corresponding to one dma channel. So we need to request dma
> channel with dma request of asrc module.
> 
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> ---
>  sound/soc/fsl/fsl_asrc.c     | 91 +++++++++++++++++++++++++++++-------
>  sound/soc/fsl/fsl_asrc.h     | 65 +++++++++++++++++++++++++-
>  sound/soc/fsl/fsl_asrc_dma.c | 39 ++++++++++++----
>  3 files changed, 167 insertions(+), 28 deletions(-)

> diff --git a/sound/soc/fsl/fsl_asrc_dma.c b/sound/soc/fsl/fsl_asrc_dma.c
> index d6146de9acd2..dbb07a486504 100644
> --- a/sound/soc/fsl/fsl_asrc_dma.c
> +++ b/sound/soc/fsl/fsl_asrc_dma.c
> @@ -199,19 +199,40 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
>  
>  	/* Get DMA request of Back-End */
>  	tmp_chan = dma_request_slave_channel(dev_be, tx ? "tx" : "rx");
> -	tmp_data = tmp_chan->private;
> -	pair->dma_data.dma_request = tmp_data->dma_request;
> -	dma_release_channel(tmp_chan);
> +	/* tmp_chan may be NULL for it is already allocated by Back-End */
> +	if (tmp_chan) {
> +		tmp_data = tmp_chan->private;
> +		if (tmp_data)
> +			pair->dma_data.dma_request = tmp_data->dma_request;

If this patch is supposed to add a !tmp_chan case for EDMA, we
probably shouldn't mute the !tmp_data case because dma_request
will be NULL, although the code previously didn't have a check
either. I mean we might need to error-out for !tmp_chan. Or...
is this intentional?

> +		dma_release_channel(tmp_chan);
> +	}
>  
>  	/* Get DMA request of Front-End */
>  	tmp_chan = fsl_asrc_get_dma_channel(pair, dir);
> -	tmp_data = tmp_chan->private;
> -	pair->dma_data.dma_request2 = tmp_data->dma_request;
> -	pair->dma_data.peripheral_type = tmp_data->peripheral_type;
> -	pair->dma_data.priority = tmp_data->priority;
> -	dma_release_channel(tmp_chan);
> +	if (tmp_chan) {
> +		tmp_data = tmp_chan->private;
> +		if (tmp_data) {

Same question here.

> +			pair->dma_data.dma_request2 = tmp_data->dma_request;
> +			pair->dma_data.peripheral_type =
> +				 tmp_data->peripheral_type;
> +			pair->dma_data.priority = tmp_data->priority;
> +		}
> +		dma_release_channel(tmp_chan);
> +	}