Re: [PATCH 28/31] PM / devfreq: imx8m-ddrc: convert to use devm_pm_opp_* API

[Chanwoo Choi <cwchoi00@xxxxxxxxx>]

On Sun, Jan 3, 2021 at 12:58 PM Yangtao Li <tiny.windzz@xxxxxxxxx> wrote:
>
> Use devm_pm_opp_* API to simplify code.
>
> Signed-off-by: Yangtao Li <tiny.windzz@xxxxxxxxx>
> ---
>  drivers/devfreq/imx8m-ddrc.c | 15 ++-------------
>  1 file changed, 2 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/devfreq/imx8m-ddrc.c b/drivers/devfreq/imx8m-ddrc.c
> index bc82d3653bff..9383d6e5538b 100644
> --- a/drivers/devfreq/imx8m-ddrc.c
> +++ b/drivers/devfreq/imx8m-ddrc.c
> @@ -370,11 +370,6 @@ static int imx8m_ddrc_check_opps(struct device *dev)
>         return 0;
>  }
>
> -static void imx8m_ddrc_exit(struct device *dev)
> -{
> -       dev_pm_opp_of_remove_table(dev);
> -}
> -
>  static int imx8m_ddrc_probe(struct platform_device *pdev)
>  {
>         struct device *dev = &pdev->dev;
> @@ -419,7 +414,7 @@ static int imx8m_ddrc_probe(struct platform_device *pdev)
>                 return ret;
>         }
>
> -       ret = dev_pm_opp_of_add_table(dev);
> +       ret = devm_pm_opp_of_add_table(dev);
>         if (ret < 0) {
>                 dev_err(dev, "failed to get OPP table\n");
>                 return ret;
> @@ -427,12 +422,11 @@ static int imx8m_ddrc_probe(struct platform_device *pdev)
>
>         ret = imx8m_ddrc_check_opps(dev);
>         if (ret < 0)
> -               goto err;
> +               return ret;
>
>         priv->profile.polling_ms = 1000;
>         priv->profile.target = imx8m_ddrc_target;
>         priv->profile.get_dev_status = imx8m_ddrc_get_dev_status;
> -       priv->profile.exit = imx8m_ddrc_exit;
>         priv->profile.get_cur_freq = imx8m_ddrc_get_cur_freq;
>         priv->profile.initial_freq = clk_get_rate(priv->dram_core);
>
> @@ -441,13 +435,8 @@ static int imx8m_ddrc_probe(struct platform_device *pdev)
>         if (IS_ERR(priv->devfreq)) {
>                 ret = PTR_ERR(priv->devfreq);
>                 dev_err(dev, "failed to add devfreq device: %d\n", ret);
> -               goto err;
>         }
>
> -       return 0;
> -
> -err:
> -       dev_pm_opp_of_remove_table(dev);
>         return ret;

devm_devfreq_add_device() doesn't return any integer value.
Even if devm_devfreq_add_device() returns the right devfreq instance,
the 'ret' value  is not the return value of  devm_devfreq_add_device().

On this patch, 'ret' value of 'return ret' is from imx8m_ddrc_check_opps().
Surely, it is well working with this modification. But, it is not code
for exception handling.
So, we need to remain the following codes:

    return 0;
err:
    return ret;

>  }
>
> --
> 2.25.1
>


-- 
Best Regards,
Chanwoo Choi