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References: <20220106030939.2644320-1-jiasheng@iscas.ac.cn>
In-Reply-To: <20220106030939.2644320-1-jiasheng@iscas.ac.cn>
From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Mon, 10 Jan 2022 10:37:34 +0100
Message-ID: <CAMuHMdWt0dWaP7Yz7CPD-ytfrCSOb4gOqp58tT+9SzNMWBqWHA@mail.gmail.com>
Subject: Re: [PATCH] dmaengine: sh: rcar-dmac: Check for error num after
 setting mask
To:     Jiasheng Jiang <jiasheng@iscas.ac.cn>
Cc:     Vinod <vkoul@kernel.org>,
        Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Wolfram Sang <wsa+renesas@sang-engineering.com>,
        Zou Wei <zou_wei@huawei.com>,
        dmaengine <dmaengine@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Precedence: bulk

Hi Jiasheng,

On Thu, Jan 6, 2022 at 4:09 AM Jiasheng Jiang <jiasheng@iscas.ac.cn> wrote:
> Because of the possible failure of the dma_supported(), the
> dma_set_mask_and_coherent() may return error num.
> Therefore, it should be better to check it and return the error if
> fails.
>
> Fixes: dc312349e875 ("dmaengine: rcar-dmac: Widen DMA mask to 40 bits")
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

> --- a/drivers/dma/sh/rcar-dmac.c
> +++ b/drivers/dma/sh/rcar-dmac.c
> @@ -1869,7 +1869,9 @@ static int rcar_dmac_probe(struct platform_device *pdev)
>         dmac->dev = &pdev->dev;
>         platform_set_drvdata(pdev, dmac);
>         dma_set_max_seg_size(dmac->dev, RCAR_DMATCR_MASK);

dma_set_max_seg_size() can fail, too.

> -       dma_set_mask_and_coherent(dmac->dev, DMA_BIT_MASK(40));
> +       ret = dma_set_mask_and_coherent(dmac->dev, DMA_BIT_MASK(40));
> +       if (ret)
> +               return ret;
>
>         ret = rcar_dmac_parse_of(&pdev->dev, dmac);
>         if (ret < 0)
> --
> 2.25.1
>


--
Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds