Re: [PATCHv3 12/15] dmaengine: fsldma: use devm for of_iomap()

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

On Tue, Jun 09, 2026 at 03:19:23PM -0700, Rosen Penev wrote:

Nit: subject: dmaengine: fsldma: use devm_of_iomap() to simplify code

> Replace of_iomap() with devm_of_iomap() for per-channel register
> mappings. This eliminates the iounmap calls in both the probe
> error path and fsl_dma_chan_remove, and simplifies the error
> handling by returning directly on failure.
>
> Assisted-by: opencode:big-pickle
> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> ---
>  drivers/dma/fsldma.c | 22 ++++++----------------
>  1 file changed, 6 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
> index 0df09789187d..a3792864f02a 100644
> --- a/drivers/dma/fsldma.c
> +++ b/drivers/dma/fsldma.c
> @@ -1111,7 +1111,6 @@ static int fsl_dma_chan_probe(struct fsldma_device *fdev,
>  {
>  	struct fsldma_chan *chan;
>  	struct resource res;
> -	int err;
>
>  	/* alloc channel */
>  	chan = devm_kzalloc(fdev->dev, sizeof(*chan), GFP_KERNEL);
> @@ -1119,17 +1118,14 @@ static int fsl_dma_chan_probe(struct fsldma_device *fdev,
>  		return -ENOMEM;
>
>  	/* ioremap registers for use */
> -	chan->regs = of_iomap(node, 0);
> -	if (!chan->regs) {
> -		dev_err(fdev->dev, "unable to ioremap registers\n");
> -		err = -ENOMEM;
> -		goto out_free_chan;
> -	}
> +	chan->regs = devm_of_iomap(fdev->dev, node, 0, NULL);
> +	if (IS_ERR(chan->regs))
> +		return dev_err_probe(fdev->dev, PTR_ERR(chan->regs), "unable to ioremap registers\n");
>
> -	err = of_address_to_resource(node, 0, &res);
> +	int err = of_address_to_resource(node, 0, &res);
>  	if (err) {
>  		dev_err(fdev->dev, "unable to find 'reg' property\n");
> -		goto out_iounmap_regs;
> +		return err;

you touch this line,

	if (err)
		return dev_err_proble(...)

Frank
>  	}
>
>  	chan->feature = feature;
> @@ -1148,8 +1144,7 @@ static int fsl_dma_chan_probe(struct fsldma_device *fdev,
>  		   ((res.start - 0x200) & 0xfff) >> 7;
>  	if (chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
>  		dev_err(fdev->dev, "too many channels for device\n");
> -		err = -EINVAL;
> -		goto out_iounmap_regs;
> +		return -EINVAL;
>  	}
>
>  	fdev->chan[chan->id] = chan;
> @@ -1195,10 +1190,6 @@ static int fsl_dma_chan_probe(struct fsldma_device *fdev,
>  		 chan->irq ? chan->irq : fdev->irq);
>
>  	return 0;
> -
> -out_iounmap_regs:
> -	iounmap(chan->regs);
> -	return err;
>  }
>
>  static void fsl_dma_chan_remove(struct fsldma_chan *chan)
> @@ -1209,7 +1200,6 @@ static void fsl_dma_chan_remove(struct fsldma_chan *chan)
>
>  	tasklet_kill(&chan->tasklet);
>  	list_del(&chan->common.device_node);
> -	iounmap(chan->regs);
>  }
>
>  static void fsldma_device_release(struct dma_device *dma_dev);
> --
> 2.54.0
>