Re: [PATCH v3 19/34] dmaengine: xilinx-dma: use dmaengine BH instead of tasklets

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

On Mon, Aug 10, 2026 at 11:09:20AM -0700, Allen Pais wrote:
> Replace the per-channel tasklet with the shared dmaengine BH helper.
> The handler continues to run in softirq context while dmaengine owns
> the common scheduling and teardown mechanism.
>
> Signed-off-by: Allen Pais <allen.lkml@gmail.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/dma/xilinx/xilinx_dma.c | 20 +++++++++-----------
>  1 file changed, 9 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
> index 404235c17353..b142c9c0583c 100644
> --- a/drivers/dma/xilinx/xilinx_dma.c
> +++ b/drivers/dma/xilinx/xilinx_dma.c
> @@ -402,7 +402,6 @@ struct xilinx_dma_tx_descriptor {
>   * @err: Channel has errors
>   * @idle: Check for channel idle
>   * @terminating: Check for channel being synchronized by user
> - * @tasklet: Cleanup work after irq
>   * @config: Device configuration info
>   * @flush_on_fsync: Flush on Frame sync
>   * @desc_pendingcount: Descriptor pending count
> @@ -441,7 +440,6 @@ struct xilinx_dma_chan {
>  	bool err;
>  	bool idle;
>  	bool terminating;
> -	struct tasklet_struct tasklet;
>  	struct xilinx_vdma_config config;
>  	bool flush_on_fsync;
>  	u32 desc_pendingcount;
> @@ -1115,11 +1113,12 @@ static void xilinx_dma_chan_desc_cleanup(struct xilinx_dma_chan *chan)
>
>  /**
>   * xilinx_dma_do_tasklet - Schedule completion tasklet
> - * @t: Pointer to the Xilinx DMA channel structure
> + * @c: Pointer to the Xilinx DMA channel structure
>   */
> -static void xilinx_dma_do_tasklet(struct tasklet_struct *t)
> +static void xilinx_dma_do_tasklet(struct dma_chan *c)
>  {
> -	struct xilinx_dma_chan *chan = from_tasklet(chan, t, tasklet);
> +	struct xilinx_dma_chan *chan = container_of(c,
> +			struct xilinx_dma_chan, common);
>
>  	xilinx_dma_chan_desc_cleanup(chan);
>  }
> @@ -1898,7 +1897,7 @@ static irqreturn_t xilinx_mcdma_irq_handler(int irq, void *data)
>  		spin_unlock(&chan->lock);
>  	}
>
> -	tasklet_hi_schedule(&chan->tasklet);
> +	dmaengine_schedule_bh(&chan->common);
>  	return IRQ_HANDLED;
>  }
>
> @@ -1955,7 +1954,7 @@ static irqreturn_t xilinx_dma_irq_handler(int irq, void *data)
>  		spin_unlock(&chan->lock);
>  	}
>
> -	tasklet_schedule(&chan->tasklet);
> +	dmaengine_schedule_bh(&chan->common);
>  	return IRQ_HANDLED;
>  }
>
> @@ -2654,7 +2653,7 @@ static void xilinx_dma_synchronize(struct dma_chan *dchan)
>  {
>  	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
>
> -	tasklet_kill(&chan->tasklet);
> +	dmaengine_kill_bh(&chan->common);
>  }
>
>  /**
> @@ -2745,7 +2744,7 @@ static void xilinx_dma_chan_remove(struct xilinx_dma_chan *chan)
>  	if (chan->irq > 0)
>  		free_irq(chan->irq, chan);
>
> -	tasklet_kill(&chan->tasklet);
> +	dmaengine_kill_bh(&chan->common);
>
>  	list_del(&chan->common.device_node);
>  }
> @@ -3075,8 +3074,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
>  			str_enabled_disabled(chan->has_sg));
>  	}
>
> -	/* Initialize the tasklet */
> -	tasklet_setup(&chan->tasklet, xilinx_dma_do_tasklet);
> +	dmaengine_init_bh(&chan->common, xilinx_dma_do_tasklet);
>
>  	/*
>  	 * Initialize the DMA channel and add it to the DMA engine channels
> --
> 2.43.0
>