Re: [PATCH] hwrng: imx-rngc: check clk_prepare_enable() return value

[Martin Kaiser <martin@kaiser.cx>]

Thus wrote Li Youhong (dayou5941@163.com):

> From: Li Youhong <liyouhong@kylinos.cn>

> The driver ignored clk_prepare_enable() failures during probe and
> resume.  If enabling the RNG clock fails, subsequent register accesses
> or resume after system sleep may not work while the driver still reports
> success.

> Signed-off-by: Li Youhong <liyouhong@kylinos.cn>
> ---
>  drivers/char/hw_random/imx-rngc.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)

> diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c
> index 7693328f1056..0545a1870146 100644
> --- a/drivers/char/hw_random/imx-rngc.c
> +++ b/drivers/char/hw_random/imx-rngc.c
> @@ -266,7 +266,9 @@ static int __init imx_rngc_probe(struct platform_device *pdev)
>  	if (irq < 0)
>  		return irq;

> -	clk_prepare_enable(rngc->clk);
> +	ret = clk_prepare_enable(rngc->clk);
> +	if (ret)
> +		return dev_err_probe(&pdev->dev, ret, "Cannot enable rng_clk\n");

>  	ver_id = readl(rngc->base + RNGC_VER_ID);
>  	rng_type = FIELD_GET(RNG_TYPE, ver_id);
> @@ -338,9 +340,7 @@ static int imx_rngc_resume(struct device *dev)
>  {
>  	struct imx_rngc *rngc = dev_get_drvdata(dev);

> -	clk_prepare_enable(rngc->clk);
> -
> -	return 0;
> +	return clk_prepare_enable(rngc->clk);
>  }

>  static const struct dev_pm_ops imx_rngc_pm_ops = {
> -- 
> 2.25.1

Reviewed-by: Martin Kaiser <martin@kaiser.cx>