Re: [PATCH] phy: mediatek: Fix missing check in mtk_mipi_tx_probe

[Chun-Kuang Hu <chunkuang.hu@kernel.org>]

Hi, Miaoqian:

Miaoqian Lin <linmq006@gmail.com> 於 2021年12月24日 週五 下午4:21寫道：
>
> The of_device_get_match_data() function may return NULL.
> Add check to prevent potential null dereference.
>
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
>  drivers/phy/mediatek/phy-mtk-mipi-dsi.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/phy/mediatek/phy-mtk-mipi-dsi.c b/drivers/phy/mediatek/phy-mtk-mipi-dsi.c
> index 28ad9403c441..67b005d5b9e3 100644
> --- a/drivers/phy/mediatek/phy-mtk-mipi-dsi.c
> +++ b/drivers/phy/mediatek/phy-mtk-mipi-dsi.c
> @@ -146,6 +146,8 @@ static int mtk_mipi_tx_probe(struct platform_device *pdev)
>                 return -ENOMEM;
>
>         mipi_tx->driver_data = of_device_get_match_data(dev);
> +       if (!mipi_tx->driver_data)

I'm confused. mtk_mipi_tx_probe() is called because this device node's
compatible match one in mtk_mipi_tx_match[]. So I think the return
value of of_device_get_match_data(dev) would not be NULL. If this is
true, this checking is redundant.

Regards,
Chun-Kuang.

> +               return -ENODEV;
>
>         mipi_tx->regs = devm_platform_ioremap_resource(pdev, 0);
>         if (IS_ERR(mipi_tx->regs))
> --
> 2.17.1
>