linux-kernel - Re: [PATCH 06/11] dmaengine: imx-sdma: make use of devm_add_action_or_reset to unregiser the dma

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Message-ID: <aLhWfPjnZZpKr/w1@lizhi-Precision-Tower-5810>
Date: Wed, 3 Sep 2025 10:53:48 -0400
From: Frank Li <Frank.li@....com>
To: Marco Felsch <m.felsch@...gutronix.de>
Cc: Vinod Koul <vkoul@...nel.org>, Shawn Guo <shawnguo@...nel.org>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	Pengutronix Kernel Team <kernel@...gutronix.de>,
	Fabio Estevam <festevam@...il.com>,
	Jiada Wang <jiada_wang@...tor.com>, dmaengine@...r.kernel.org,
	imx@...ts.linux.dev, linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 06/11] dmaengine: imx-sdma: make use of
 devm_add_action_or_reset to unregiser the dma_device

On Wed, Sep 03, 2025 at 03:06:14PM +0200, Marco Felsch wrote:
> Make use of the devm_add_action_or_reset() to register a custom devm_
> release hook. This is required since we want to turn of the IRQs before

turn off?

> doing the dma_async_device_unregister().
>
> This removes the last goto error handling within the probe function and

Remove the last ..

> further trims the remove() function. Instead of freeing the irq, we can
> disable it and let the devm-irq do the job to free the irq, since the
> only purpose was to have the irqs disabled before calling
> dma_async_device_unregister().
>
> Signed-off-by: Marco Felsch <m.felsch@...gutronix.de>
> ---
>  drivers/dma/imx-sdma.c | 19 +++++++++++--------
>  1 file changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
> index 5a571d3f33158813e0c56484600a49b19a6a72e2..f6bb2f88a62781c0431336c365fa30c46f1401ad 100644
> --- a/drivers/dma/imx-sdma.c
> +++ b/drivers/dma/imx-sdma.c
> @@ -2232,6 +2232,14 @@ static struct dma_chan *sdma_xlate(struct of_phandle_args *dma_spec,
>  				     ofdma->of_node);
>  }
>
> +static void sdma_dma_device_unregister_action(void *data)
> +{
> +	struct sdma_engine *sdma = data;
> +
> +	disable_irq(sdma->irq);
> +	dma_async_device_unregister(&sdma->dma_device);
> +}
> +
>  static int sdma_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
> @@ -2358,10 +2366,12 @@ static int sdma_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>
> +	devm_add_action_or_reset(dev, sdma_dma_device_unregister_action, sdma);
> +

need check return value.

Frank

>  	ret = of_dma_controller_register(np, sdma_xlate, sdma);
>  	if (ret) {
>  		dev_err(dev, "failed to register controller\n");
> -		goto err_register;
> +		return ret;
>  	}
>
>  	spba_bus = of_find_compatible_node(NULL, NULL, "fsl,spba-bus");
> @@ -2388,11 +2398,6 @@ static int sdma_probe(struct platform_device *pdev)
>  	}
>
>  	return 0;
> -
> -err_register:
> -	dma_async_device_unregister(&sdma->dma_device);
> -
> -	return ret;
>  }
>
>  static void sdma_remove(struct platform_device *pdev)
> @@ -2400,8 +2405,6 @@ static void sdma_remove(struct platform_device *pdev)
>  	struct sdma_engine *sdma = platform_get_drvdata(pdev);
>  	int i;
>
> -	devm_free_irq(&pdev->dev, sdma->irq, sdma);
> -	dma_async_device_unregister(&sdma->dma_device);
>  	/* Kill the tasklet */
>  	for (i = 0; i < MAX_DMA_CHANNELS; i++) {
>  		struct sdma_channel *sdmac = &sdma->channel[i];
>
> --
> 2.47.2
>