Re: [PATCH] staging: fix ignoring return value warning

[Sascha Hauer]

On Sun, Feb 07, 2021 at 05:23:28PM +0800, Youling Tang wrote:
> Fix the below ignoring return value warning for device_reset.
> 
> drivers/staging/mt7621-dma/mtk-hsdma.c:685:2: warning: ignoring return value
> of function declared with 'warn_unused_result' attribute [-Wunused-result]
>         device_reset(&pdev->dev);
>         ^~~~~~~~~~~~ ~~~~~~~~~~
> drivers/staging/ralink-gdma/ralink-gdma.c:836:2: warning: ignoring return value
> of function declared with 'warn_unused_result' attribute [-Wunused-result]
>         device_reset(&pdev->dev);
>         ^~~~~~~~~~~~ ~~~~~~~~~~
> 
> Signed-off-by: Youling Tang <tangyouling@xxxxxxxxxxx>
> ---
>  drivers/staging/mt7621-dma/mtk-hsdma.c    | 6 +++++-
>  drivers/staging/ralink-gdma/ralink-gdma.c | 6 +++++-
>  2 files changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/mt7621-dma/mtk-hsdma.c b/drivers/staging/mt7621-dma/mtk-hsdma.c
> index bc4bb43..d4ffa52 100644
> --- a/drivers/staging/mt7621-dma/mtk-hsdma.c
> +++ b/drivers/staging/mt7621-dma/mtk-hsdma.c
> @@ -682,7 +682,11 @@ static int mtk_hsdma_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> -	device_reset(&pdev->dev);
> +	ret = device_reset(&pdev->dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to reset device\n");
> +		return ret;
> +	}

Normally you don't want to see this error message when -EPROBE_DEFER is
returned because that would mean the reset controller is not yet
available and the driver should probe later again. There is
dev_err_probe() now for exactly this usecase.

Sascha

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