Re: [PATCH v5 4/5] dmaengine: imx-sdma: add a test for imx8mq multi sdma devices

[Lucas Stach]

Am Sonntag, den 27.01.2019, 23:08 -0700 schrieb Angus Ainslie (Purism):
> On i.mx8mq, there are two sdma instances, and the common dma framework
> will get a channel dynamically from any available sdma instance whether
> it's the first sdma device or the second sdma device. Some IPs like
> SAI only work with sdma2 not sdma1. To make sure the sdma channel is from
> the correct sdma device, use the node pointer to match.
> 
> Signed-off-by: Angus Ainslie (Purism) <angus@xxxxxxxx>

Reviewed-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>

> ---
>  drivers/dma/imx-sdma.c                | 6 ++++++
>  include/linux/platform_data/dma-imx.h | 1 +
>  2 files changed, 7 insertions(+)
> 
> diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
> index c4db4fe6bcc9..d5f86becf59e 100644
> --- a/drivers/dma/imx-sdma.c
> +++ b/drivers/dma/imx-sdma.c
> @@ -1918,11 +1918,16 @@ static int sdma_init(struct sdma_engine *sdma)
>  static bool sdma_filter_fn(struct dma_chan *chan, void *fn_param)
>  {
>  	struct sdma_channel *sdmac = to_sdma_chan(chan);
> +	struct sdma_engine *sdma = sdmac->sdma;
>  	struct imx_dma_data *data = fn_param;
>  
>  	if (!imx_dma_is_general_purpose(chan))
>  		return false;
>  
> +	/* return false if it's not the right device */
> +	if (sdma->dev->of_node != data->of_node)
> +		return false;
> +
>  	sdmac->data = *data;
>  	chan->private = &sdmac->data;
>  
> @@ -1950,6 +1955,7 @@ static struct dma_chan *sdma_xlate(struct of_phandle_args *dma_spec,
>  	 * be set to sdmac->event_id1.
>  	 */
>  	data.dma_request2 = 0;
> +	data.of_node = ofdma->of_node;
>  
>  	return dma_request_channel(mask, sdma_filter_fn, &data);
>  }
> diff --git a/include/linux/platform_data/dma-imx.h b/include/linux/platform_data/dma-imx.h
> index 7d964e787299..9daea8d42a10 100644
> --- a/include/linux/platform_data/dma-imx.h
> +++ b/include/linux/platform_data/dma-imx.h
> @@ -55,6 +55,7 @@ struct imx_dma_data {
>  	int dma_request2; /* secondary DMA request line */
>  	enum sdma_peripheral_type peripheral_type;
>  	int priority;
> +	struct device_node *of_node;
>  };
>  
>  static inline int imx_dma_is_ipu(struct dma_chan *chan)