Re: [PATCH v3 1/3] dma: Support multiple interleaved frames with non-contiguous memory

[Vinod Koul <vinod.koul@intel.com>]

On Sat, Feb 15, 2014 at 05:30:17PM +0530, Srikanth Thokala wrote:
> The current implementation of interleaved DMA API support multiple
> frames only when the memory is contiguous by incrementing src_start/
> dst_start members of interleaved template.
> 
> But, when the memory is non-contiguous it will restrict slave device
> to not submit multiple frames in a batch.  This patch handles this
> issue by allowing the slave device to send array of interleaved dma
> templates each having a different memory location.
This seems to be missing the numbers of templates you are sending, wouldnt this
require sending ARRAY_SiZE too?

And why send double pointer?

-- 
~Vinod

> 
> Signed-off-by: Srikanth Thokala <sthokal@xilinx.com>
> ---
>  Documentation/dmaengine.txt              |    2 +-
>  drivers/dma/imx-dma.c                    |    3 ++-
>  drivers/dma/sirf-dma.c                   |    3 ++-
>  drivers/media/platform/m2m-deinterlace.c |    2 +-
>  include/linux/dmaengine.h                |    6 +++---
>  5 files changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/Documentation/dmaengine.txt b/Documentation/dmaengine.txt
> index 879b6e3..c642614 100644
> --- a/Documentation/dmaengine.txt
> +++ b/Documentation/dmaengine.txt
> @@ -94,7 +94,7 @@ The slave DMA usage consists of following steps:
>  		size_t period_len, enum dma_data_direction direction);
>  
>  	struct dma_async_tx_descriptor *(*device_prep_interleaved_dma)(
> -		struct dma_chan *chan, struct dma_interleaved_template *xt,
> +		struct dma_chan *chan, struct dma_interleaved_template **xts,
>  		unsigned long flags);
>  
>     The peripheral driver is expected to have mapped the scatterlist for
> diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c
> index 6f9ac20..e2c52ce 100644
> --- a/drivers/dma/imx-dma.c
> +++ b/drivers/dma/imx-dma.c
> @@ -954,12 +954,13 @@ static struct dma_async_tx_descriptor *imxdma_prep_dma_memcpy(
>  }
>  
>  static struct dma_async_tx_descriptor *imxdma_prep_dma_interleaved(
> -	struct dma_chan *chan, struct dma_interleaved_template *xt,
> +	struct dma_chan *chan, struct dma_interleaved_template **xts,
>  	unsigned long flags)
>  {
>  	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
>  	struct imxdma_engine *imxdma = imxdmac->imxdma;
>  	struct imxdma_desc *desc;
> +	struct dma_interleaved_template *xt = *xts;
>  
>  	dev_dbg(imxdma->dev, "%s channel: %d src_start=0x%llx dst_start=0x%llx\n"
>  		"   src_sgl=%s dst_sgl=%s numf=%zu frame_size=%zu\n", __func__,
> diff --git a/drivers/dma/sirf-dma.c b/drivers/dma/sirf-dma.c
> index d4d3a31..b6a150b 100644
> --- a/drivers/dma/sirf-dma.c
> +++ b/drivers/dma/sirf-dma.c
> @@ -509,12 +509,13 @@ sirfsoc_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
>  }
>  
>  static struct dma_async_tx_descriptor *sirfsoc_dma_prep_interleaved(
> -	struct dma_chan *chan, struct dma_interleaved_template *xt,
> +	struct dma_chan *chan, struct dma_interleaved_template **xts,
>  	unsigned long flags)
>  {
>  	struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(chan);
>  	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
>  	struct sirfsoc_dma_desc *sdesc = NULL;
> +	struct dma_interleaved_template *xt = *xts;
>  	unsigned long iflags;
>  	int ret;
>  
> diff --git a/drivers/media/platform/m2m-deinterlace.c b/drivers/media/platform/m2m-deinterlace.c
> index 6bb86b5..468110a 100644
> --- a/drivers/media/platform/m2m-deinterlace.c
> +++ b/drivers/media/platform/m2m-deinterlace.c
> @@ -343,7 +343,7 @@ static void deinterlace_issue_dma(struct deinterlace_ctx *ctx, int op,
>  	ctx->xt->dst_sgl = true;
>  	flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
>  
> -	tx = dmadev->device_prep_interleaved_dma(chan, ctx->xt, flags);
> +	tx = dmadev->device_prep_interleaved_dma(chan, &ctx->xt, flags);
>  	if (tx == NULL) {
>  		v4l2_warn(&pcdev->v4l2_dev, "DMA interleaved prep error\n");
>  		return;
> diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
> index c5c92d5..2f77a9a 100644
> --- a/include/linux/dmaengine.h
> +++ b/include/linux/dmaengine.h
> @@ -675,7 +675,7 @@ struct dma_device {
>  		size_t period_len, enum dma_transfer_direction direction,
>  		unsigned long flags, void *context);
>  	struct dma_async_tx_descriptor *(*device_prep_interleaved_dma)(
> -		struct dma_chan *chan, struct dma_interleaved_template *xt,
> +		struct dma_chan *chan, struct dma_interleaved_template **xts,
>  		unsigned long flags);
>  	int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
>  		unsigned long arg);
> @@ -752,10 +752,10 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_cyclic(
>  }
>  
>  static inline struct dma_async_tx_descriptor *dmaengine_prep_interleaved_dma(
> -		struct dma_chan *chan, struct dma_interleaved_template *xt,
> +		struct dma_chan *chan, struct dma_interleaved_template **xts,
>  		unsigned long flags)
>  {
> -	return chan->device->device_prep_interleaved_dma(chan, xt, flags);
> +	return chan->device->device_prep_interleaved_dma(chan, xts, flags);
>  }
>  
>  static inline int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
> -- 
> 1.7.9.5
> 
> --
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