Re: [PATCH v2 03/19] dmaengine: dw-edma: Factor out linked-list transfer start

[Frank Li]

On Thu, Jul 23, 2026 at 05:41:34PM +0900, Koichiro Den wrote:
> Move linked-list programming into dw_edma_core_ll_start(). It can derive
> the first-batch state from desc->start_burst, so dw_edma_core_start() no
> longer needs a pass-through argument.
>
> No functional change intended.
>
> Signed-off-by: Koichiro Den <den@xxxxxxxxxxxxx>
> ---

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>

> Changes in v2:
>   - New patch.
>
>  drivers/dma/dw-edma/dw-edma-core.c | 29 +++++++++++++++++++----------
>  1 file changed, 19 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
> index 1f893dc54c79..6a25a050b89c 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-core.c
> @@ -67,17 +67,11 @@ static void vchan_free_desc(struct virt_dma_desc *vdesc)
>  	kfree(vd2dw_edma_desc(vdesc));
>  }
>
> -static void dw_edma_core_start(struct dw_edma_desc *desc, bool first)
> +static void dw_edma_core_ll_start(struct dw_edma_desc *desc)
>  {
>  	struct dw_edma_chan *chan = desc->chan;
> -	size_t i = 0;
> -
> -	if (chan->non_ll) {
> -		chan->dw->core->non_ll_start(chan, &desc->burst[desc->start_burst]);
> -		desc->done_burst = desc->start_burst;
> -		desc->start_burst += 1;
> -		return;
> -	}
> +	size_t i;
> +	bool first = !desc->start_burst;
>
>  	for (i = 0; i + desc->start_burst < desc->nburst; i++) {
>  		u32 idx = i + desc->start_burst;
> @@ -101,6 +95,21 @@ static void dw_edma_core_start(struct dw_edma_desc *desc, bool first)
>  	dw_edma_core_ch_doorbell(chan);
>  }
>
> +static void dw_edma_core_start(struct dw_edma_desc *desc)
> +{
> +	struct dw_edma_chan *chan = desc->chan;
> +
> +	if (chan->non_ll) {
> +		chan->dw->core->non_ll_start(chan,
> +					     &desc->burst[desc->start_burst]);
> +		desc->done_burst = desc->start_burst;
> +		desc->start_burst += 1;
> +		return;
> +	}
> +
> +	dw_edma_core_ll_start(desc);
> +}
> +
>  static int dw_edma_start_transfer(struct dw_edma_chan *chan)
>  {
>  	struct dw_edma_desc *desc;
> @@ -114,7 +123,7 @@ static int dw_edma_start_transfer(struct dw_edma_chan *chan)
>  	if (!desc)
>  		return 0;
>
> -	dw_edma_core_start(desc, !desc->start_burst);
> +	dw_edma_core_start(desc);
>
>  	desc->cb = !desc->cb;
>
> --
> 2.51.0
>