linux-kernel - Re: [PATCH 1/2] dmaengine: fsl-edma: cleanup chan after dma_async_device

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Message-ID: <ZyUdktvfqAK5IIG9@lizhi-Precision-Tower-5810>
Date: Fri, 1 Nov 2024 14:27:30 -0400
From: Frank Li <Frank.li@....com>
To: "Peng Fan (OSS)" <peng.fan@....nxp.com>
Cc: Vinod Koul <vkoul@...nel.org>,
	"open list:FREESCALE eDMA DRIVER" <imx@...ts.linux.dev>,
	"open list:FREESCALE eDMA DRIVER" <dmaengine@...r.kernel.org>,
	open list <linux-kernel@...r.kernel.org>,
	Peng Fan <peng.fan@....com>
Subject: Re: [PATCH 1/2] dmaengine: fsl-edma: cleanup chan after
 dma_async_device_unregister

On Fri, Nov 01, 2024 at 06:14:09PM +0800, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@....com>
>
> There is kernel dump when do module test:
> sysfs: cannot create duplicate filename '/devices/platform/soc@...4000000.bus/44000000.dma-controller/dma/dma0chan0'
>  __dma_async_device_channel_register+0x128/0x19c
>  dma_async_device_register+0x150/0x454
>  fsl_edma_probe+0x6cc/0x8a0
>  platform_probe+0x68/0xc8
>
> Clean up chan after dma_async_device_unregister to address this.

Can you explan why move it after dma_async_device_unregiste() can fix this
problem?

Frank
>
> Fixes: 6f93b93b2a1b ("dmaengine: fsl-edma: kill the tasklets upon exit")
> Signed-off-by: Peng Fan <peng.fan@....com>
> ---
>  drivers/dma/fsl-edma-main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/fsl-edma-main.c b/drivers/dma/fsl-edma-main.c
> index f9f1eda79254..01bd5cb24a49 100644
> --- a/drivers/dma/fsl-edma-main.c
> +++ b/drivers/dma/fsl-edma-main.c
> @@ -668,9 +668,9 @@ static void fsl_edma_remove(struct platform_device *pdev)
>  	struct fsl_edma_engine *fsl_edma = platform_get_drvdata(pdev);
>
>  	fsl_edma_irq_exit(pdev, fsl_edma);
> -	fsl_edma_cleanup_vchan(&fsl_edma->dma_dev);
>  	of_dma_controller_free(np);
>  	dma_async_device_unregister(&fsl_edma->dma_dev);
> +	fsl_edma_cleanup_vchan(&fsl_edma->dma_dev);
>  	fsl_disable_clocks(fsl_edma, fsl_edma->drvdata->dmamuxs);
>  }
>
> --
> 2.37.1
>