Re: [PATCH v3 24/34] dmaengine: txx9dmac: route callbacks via channel BH

[Frank Li]

On Mon, Aug 10, 2026 at 11:09:25AM -0700, Allen Pais wrote:
> Use the per-channel BH helpers for descriptor completion handling and
> schedule per-channel work from both channel and controller IRQ paths.
>
> Signed-off-by: Allen Pais <allen.lkml@xxxxxxxxx>
> ---

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

>  drivers/dma/txx9dmac.c | 12 ++++++------
>  drivers/dma/txx9dmac.h |  1 -
>  2 files changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/dma/txx9dmac.c b/drivers/dma/txx9dmac.c
> index 05622b68a936..0547f645b51c 100644
> --- a/drivers/dma/txx9dmac.c
> +++ b/drivers/dma/txx9dmac.c
> @@ -601,13 +601,13 @@ static void txx9dmac_scan_descriptors(struct txx9dmac_chan *dc)
>  	}
>  }
>
> -static void txx9dmac_chan_tasklet(struct tasklet_struct *t)
> +static void txx9dmac_chan_tasklet(struct dma_chan *chan)
>  {
>  	int irq;
>  	u32 csr;
>  	struct txx9dmac_chan *dc;
>
> -	dc = from_tasklet(dc, t, tasklet);
> +	dc = container_of(chan, struct txx9dmac_chan, chan);
>  	csr = channel_readl(dc, CSR);
>  	dev_vdbg(chan2dev(&dc->chan), "tasklet: status=%x\n", csr);
>
> @@ -628,7 +628,7 @@ static irqreturn_t txx9dmac_chan_interrupt(int irq, void *dev_id)
>  	dev_vdbg(chan2dev(&dc->chan), "interrupt: status=%#x\n",
>  			channel_readl(dc, CSR));
>
> -	tasklet_schedule(&dc->tasklet);
> +	dmaengine_schedule_bh(&dc->chan);
>  	/*
>  	 * Just disable the interrupts. We'll turn them back on in the
>  	 * softirq handler.
> @@ -659,7 +659,7 @@ static void txx9dmac_tasklet(struct tasklet_struct *t)
>  			spin_lock(&dc->lock);
>  			if (csr & (TXX9_DMA_CSR_ABCHC | TXX9_DMA_CSR_NCHNC |
>  				   TXX9_DMA_CSR_NTRNFC))
> -				txx9dmac_scan_descriptors(dc);
> +				dmaengine_schedule_bh(&dc->chan);
>  			spin_unlock(&dc->lock);
>  		}
>  	}
> @@ -1113,7 +1113,7 @@ static int __init txx9dmac_chan_probe(struct platform_device *pdev)
>  		irq = platform_get_irq(pdev, 0);
>  		if (irq < 0)
>  			return irq;
> -		tasklet_setup(&dc->tasklet, txx9dmac_chan_tasklet);
> +		dmaengine_init_bh(&dc->chan, txx9dmac_chan_tasklet);
>  		dc->irq = irq;
>  		err = devm_request_irq(&pdev->dev, dc->irq,
>  			txx9dmac_chan_interrupt, 0, dev_name(&pdev->dev), dc);
> @@ -1159,7 +1159,7 @@ static void txx9dmac_chan_remove(struct platform_device *pdev)
>  	dma_async_device_unregister(&dc->dma);
>  	if (dc->irq >= 0) {
>  		devm_free_irq(&pdev->dev, dc->irq, dc);
> -		tasklet_kill(&dc->tasklet);
> +		dmaengine_kill_bh(&dc->chan);
>  	}
>  	dc->ddev->chan[pdev->id % TXX9_DMA_MAX_NR_CHANNELS] = NULL;
>  }
> diff --git a/drivers/dma/txx9dmac.h b/drivers/dma/txx9dmac.h
> index aa53eafb1519..f2abedb73d49 100644
> --- a/drivers/dma/txx9dmac.h
> +++ b/drivers/dma/txx9dmac.h
> @@ -162,7 +162,6 @@ struct txx9dmac_chan {
>  	struct dma_device	dma;
>  	struct txx9dmac_dev	*ddev;
>  	void __iomem		*ch_regs;
> -	struct tasklet_struct	tasklet;
>  	int			irq;
>  	u32			ccr;
>
> --
> 2.43.0
>