Re: [PATCH V2 2/5] dmaengine: xilinx_dma: Move descriptors to done list based on completion bit

[Frank Li <Frank.li@nxp.com>]

On Fri, Mar 13, 2026 at 11:55:30AM +0530, Srinivas Neeli wrote:
> In AXIMCDMA scatter-gather mode, the hardware sets the completion bit when
> a transfer finishes. The driver now checks this bit to free descriptors
> from the active list and move them to the done list.

Add check complete bit because irq may be triggered before a configured
threshold is reached when interrupt delay timeout Dly_IrqEn is enabled.

Frank

> This is required when interrupt delay timeout Dly_IrqEn is enabled,
> as interrupts may be triggered before the configured threshold is reached,
> even if not all descriptors have completed.
>
> Signed-off-by: Srinivas Neeli <srinivas.neeli@amd.com>
> ---
>  drivers/dma/xilinx/xilinx_dma.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
> index 4a83492f2435..00200b4c2372 100644
> --- a/drivers/dma/xilinx/xilinx_dma.c
> +++ b/drivers/dma/xilinx/xilinx_dma.c
> @@ -1762,6 +1762,18 @@ static void xilinx_dma_complete_descriptor(struct xilinx_dma_chan *chan)
>  					      struct xilinx_axidma_tx_segment, node);
>  			if (!(seg->hw.status & XILINX_DMA_BD_COMP_MASK) && chan->has_sg)
>  				break;
> +		} else if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIMCDMA) {
> +			struct xilinx_aximcdma_tx_segment *seg;
> +			bool completed;
> +
> +			seg = list_last_entry(&desc->segments,
> +					      struct xilinx_aximcdma_tx_segment,
> +					      node);
> +			completed = (chan->direction == DMA_DEV_TO_MEM) ?
> +				(seg->hw.s2mm_status & XILINX_DMA_BD_COMP_MASK) :
> +				(seg->hw.mm2s_status & XILINX_DMA_BD_COMP_MASK);
> +			if (!completed)
> +				break;
>  		}
>  		if (chan->has_sg && chan->xdev->dma_config->dmatype !=
>  		    XDMA_TYPE_VDMA)
> --
> 2.43.0
>