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: <20250910101328.7rp5ulsrahpqfdtz@pengutronix.de>
Date: Wed, 10 Sep 2025 12:13:28 +0200
From: Marco Felsch <m.felsch@...gutronix.de>
To: Frank Li <Frank.li@....com>
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 25-09-03, Frank Li wrote:
> 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 ..

I rephrased the commit message.

> > 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.

Sure, thanks.

Regards,
  Marco

> 
> 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
> >
>