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

Marco Felsch
2025-09-12T15:25:29Z

On 25-09-12, Frank Li wrote:
> 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.

You mean by setting irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY)
infront? Not sure if this is required since this is just the cleanup
path.

> > + 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?

Please see my last patch.

Regards,
Marco

>
> > +
> > 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
> >
>