Re: [PATCH v2 08/10] dmaengine: imx-sdma: make use of devm_add_action_or_reset to unregiser the dma_device

Frank Li
2025-09-12T14:49:54Z

On Thu, Sep 11, 2025 at 11:56:49PM +0200, Marco Felsch wrote:
> Make use of the devm_add_action_or_reset() to register a custom devm_
> release hook. This is required to turn off the IRQs before calling
> dma_async_device_unregister().
>
> Furthermore it removes the last goto error handling within probe() and
> trims the remove().
>
> Make use of disable_irq() and let the devm-irq do the job to free the
> IRQ, because the only purpose of using devm_free_irq() was to disable
> the IRQ before calling dma_async_device_unregister().
>
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
> drivers/dma/imx-sdma.c | 23 +++++++++++++++--------
> 1 file changed, 15 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
> index d39589c20c4b2a26d0239feb86cce8d5a0f5acdd..d6d0d4300f540268a3ab4a6b14af685f7b93275a 100644
> --- a/drivers/dma/imx-sdma.c
> +++ b/drivers/dma/imx-sdma.c
> @@ -2264,6 +2264,14 @@ 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);

May not related this cleanup patch, I am just curious why not mask sdma irq
request.

> + dma_async_device_unregister(&sdma->dma_device);
> +}
> +
> static int sdma_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> @@ -2388,10 +2396,16 @@ static int sdma_probe(struct platform_device *pdev)
> return ret;
> }
>
> + ret = devm_add_action_or_reset(dev, sdma_dma_device_unregister_action, sdma);
> + if (ret) {
> + dev_err(dev, "Unable to register release hook\n");
> + return ret;
> + }

why not use dev_err_probe() her?

> +
> ret = of_dma_controller_register(np, sdma_xlate, sdma);
> if (ret) {
> dev_err(dev, "failed to register controller\n");
> - goto err_register;
> + return ret;

the same here.

Frank
> }
>
> /*
> @@ -2410,11 +2424,6 @@ 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)
> @@ -2423,8 +2432,6 @@ static void sdma_remove(struct platform_device *pdev)
> int i;
>
> of_dma_controller_free(sdma->dev->of_node);
> - 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];
>
> --
> 2.47.3
>