linux-kernel - Re: [PATCH] dmaengine: fsl-edma: disable clks on all error paths

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Date:   Wed, 6 Dec 2017 14:20:45 +0100
From:   Andreas Platschek <andreas.platschek@...ntech.at>
To:     vinod.koul@...el.com
Cc:     dmaengine@...r.kernel.org, linux-kernel@...r.kernel.org,
        dan.j.williams@...el.com
Subject: Re: [PATCH] dmaengine: fsl-edma: disable clks on all error paths

Hi,

On Wed, 06 Dec 2017, Andreas Platschek wrote:

> Previously enabled clks are only disabled if clk_prepare_enable() fails.
> However, there are other error paths were the previously enabled
> clocks are not disabled.
> 
> Found by Linux Driver Verification project (linuxtesting.org).
> 
> Signed-off-by: Andreas Platschek <andreas.platschek@...ntech.at>
> ---
>  drivers/dma/fsl-edma.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c
> index 6775f2c74e25..ccb447253cd2 100644
> --- a/drivers/dma/fsl-edma.c
> +++ b/drivers/dma/fsl-edma.c
> @@ -904,12 +904,23 @@ static int fsl_edma_probe(struct platform_device *pdev)
>  
>  		res = platform_get_resource(pdev, IORESOURCE_MEM, 1 + i);
>  		fsl_edma->muxbase[i] = devm_ioremap_resource(&pdev->dev, res);
> -		if (IS_ERR(fsl_edma->muxbase[i]))
> +		if (IS_ERR(fsl_edma->muxbase[i])) {
> +			/* disable only clks which were enabled on error */
> +			i--;
> +			for (; i >= 0; i--)
> +				clk_disable_unprepare(fsl_edma->muxclk[i]);
> +
>  			return PTR_ERR(fsl_edma->muxbase[i]);

just realized that I made a stupid mistake and overlooked that i is used again...

sorry for the noise I'll go over this again.

thx!
andi

> +		}
>  
>  		sprintf(clkname, "dmamux%d", i);
>  		fsl_edma->muxclk[i] = devm_clk_get(&pdev->dev, clkname);
>  		if (IS_ERR(fsl_edma->muxclk[i])) {
> +			/* disable only clks which were enabled on error */
> +			i--;
> +			for (; i >= 0; i--)
> +				clk_disable_unprepare(fsl_edma->muxclk[i]);
> +
>  			dev_err(&pdev->dev, "Missing DMAMUX block clock.\n");
>  			return PTR_ERR(fsl_edma->muxclk[i]);
>  		}
> -- 
> 2.11.0
>