Hi Yangtao,

On Tue, Jan 5, 2021 at 1:13 PM Chanwoo Choi [off-list ref] wrote:

On Sun, Jan 3, 2021 at 12:58 PM Yangtao Li [off-list ref] wrote:

quoted

Use devm_pm_opp_* API to simplify code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
---
 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;

'err' is not necessary. You better to edit it as following:

if (IS_ERR(priv->devfreq)) {
    dev_err(dev, "failed to add devfreq device: %d\n", ret);
    return PTR_ERR(priv->devfreq);
}

return 0;

-- 
Best Regards,
Chanwoo Choi