Hi Wen,
Wen Yang <yellowriver2...@hotmail.com> wrote on Thu, 7 Feb 2019
12:02:45 +0000:
> of_find_device_by_node() takes a reference to the struct device
> when it finds a match via get_device, there is no need to call
> get_device() twice.
> We also should make sure to drop the reference to the device
> taken by of_find_device_by_node() on driver unbind.
>
> Fixes: ae02ab00aa3c ("mtd: nand: jz4780: driver for NAND devices on JZ4780
> SoCs")
> Signed-off-by: Wen Yang <yellowriver2...@hotmail.com>
> ---
> v4->v3: Add people in Cc and remove all lines.
> v3->v2: Avoid two times of calling grtform_get_drvdata()
> v2->v1: Since there is the only one user, let's remove the err_put_device
> label.
>
> drivers/mtd/nand/raw/jz4780_bch.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/jz4780_bch.c
> b/drivers/mtd/nand/raw/jz4780_bch.c
> index 7201827..7aab851 100644
> --- a/drivers/mtd/nand/raw/jz4780_bch.c
> +++ b/drivers/mtd/nand/raw/jz4780_bch.c
> @@ -281,12 +281,14 @@ static struct jz4780_bch *jz4780_bch_get(struct
> device_node *np)
> struct jz4780_bch *bch;
>
> pdev = of_find_device_by_node(np);
> - if (!pdev || !platform_get_drvdata(pdev))
> + if (!pdev)
> return ERR_PTR(-EPROBE_DEFER);
> -
> - get_device(&pdev->dev);
> -
Please keep one blank line here.
> bch = platform_get_drvdata(pdev);
> + if (!bch) {
> + put_device(&pdev->dev);
> + return ERR_PTR(-EPROBE_DEFER);
> + }
> +
> clk_prepare_enable(bch->clk);
>
> return bch;
Thanks,
Miquèl
