linux-kernel - Re: [PATCH 1/2] mmc: moxart: remove unneeded check for drvdata

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Date:   Thu, 24 Sep 2020 14:49:48 +0200
From:   Ulf Hansson <ulf.hansson@...aro.org>
To:     Krzysztof Kozlowski <krzk@...nel.org>
Cc:     Adrian Hunter <adrian.hunter@...el.com>,
        Shawn Guo <shawnguo@...nel.org>,
        Sascha Hauer <s.hauer@...gutronix.de>,
        Pengutronix Kernel Team <kernel@...gutronix.de>,
        Fabio Estevam <festevam@...il.com>,
        NXP Linux Team <linux-imx@....com>,
        Orson Zhai <orsonzhai@...il.com>,
        Baolin Wang <baolin.wang7@...il.com>,
        Chunyan Zhang <zhang.lyra@...il.com>,
        "linux-mmc@...r.kernel.org" <linux-mmc@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH 1/2] mmc: moxart: remove unneeded check for drvdata

On Wed, 23 Sep 2020 at 17:37, Krzysztof Kozlowski <krzk@...nel.org> wrote:
>
> The 'struct mmc_host *mmc' comes from drvdata set at the end of probe,
> so it cannot be NULL.  The code already dereferences it few lines before
> the check with mmc_priv().  This also fixes smatch warning:
>
>   drivers/mmc/host/moxart-mmc.c:692 moxart_remove() warn: variable dereferenced before check 'mmc' (see line 688)
>
> Reported-by: kernel test robot <lkp@...el.com>
> Reported-by: Dan Carpenter <dan.carpenter@...cle.com>
> Signed-off-by: Krzysztof Kozlowski <krzk@...nel.org>

Applied for next, thanks!

Kind regards
Uffe


> ---
>  drivers/mmc/host/moxart-mmc.c | 23 +++++++++++------------
>  1 file changed, 11 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/mmc/host/moxart-mmc.c b/drivers/mmc/host/moxart-mmc.c
> index 2bfb376fddc4..f25079ba3bca 100644
> --- a/drivers/mmc/host/moxart-mmc.c
> +++ b/drivers/mmc/host/moxart-mmc.c
> @@ -689,19 +689,18 @@ static int moxart_remove(struct platform_device *pdev)
>
>         dev_set_drvdata(&pdev->dev, NULL);
>
> -       if (mmc) {
> -               if (!IS_ERR(host->dma_chan_tx))
> -                       dma_release_channel(host->dma_chan_tx);
> -               if (!IS_ERR(host->dma_chan_rx))
> -                       dma_release_channel(host->dma_chan_rx);
> -               mmc_remove_host(mmc);
> -               mmc_free_host(mmc);
> +       if (!IS_ERR(host->dma_chan_tx))
> +               dma_release_channel(host->dma_chan_tx);
> +       if (!IS_ERR(host->dma_chan_rx))
> +               dma_release_channel(host->dma_chan_rx);
> +       mmc_remove_host(mmc);
> +       mmc_free_host(mmc);
> +
> +       writel(0, host->base + REG_INTERRUPT_MASK);
> +       writel(0, host->base + REG_POWER_CONTROL);
> +       writel(readl(host->base + REG_CLOCK_CONTROL) | CLK_OFF,
> +              host->base + REG_CLOCK_CONTROL);
>
> -               writel(0, host->base + REG_INTERRUPT_MASK);
> -               writel(0, host->base + REG_POWER_CONTROL);
> -               writel(readl(host->base + REG_CLOCK_CONTROL) | CLK_OFF,
> -                      host->base + REG_CLOCK_CONTROL);
> -       }
>         return 0;
>  }
>
> --
> 2.17.1
>