Re: [PATCH] devfreq: rk3399_dmc: Fix duplicated opp table on reload.

Hi Enric,

On 2018년 06월 18일 18:10, Enric Balletbo Serra wrote:

Hi Chanwoo,

Missatge de Chanwoo Choi [off-list ref] del dia dg., 17 de juny
2018 a les 5:23:

quoted

Hi Enric,

2018-06-16 0:12 GMT+09:00 Enric Balletbo i Serra [off-list ref]:

quoted

The opp table is not removed when the driver is unloaded neither when
there is an error within probe, so if the driver is reloaded the opp
core shows the following warning:

  rk3399-dmc-freq dmc: _opp_add: duplicate OPPs detected. Existing: freq:
               200000000, volt: 900000, enabled: 1. New: freq: 200000000,
               volt: 900000, enabled: 1
  rk3399-dmc-freq dmc: _opp_add: duplicate OPPs detected. Existing: freq:
               400000000, volt: 900000, enabled: 1. New: freq: 400000000,
               volt: 900000, enabled: 1
  rk3399-dmc-freq dmc: _opp_add: duplicate OPPs detected. Existing: freq:
               666000000, volt: 900000, enabled: 1. New: freq: 666000000,
               volt: 900000, enabled: 1
  rk3399-dmc-freq dmc: _opp_add: duplicate OPPs detected. Existing: freq:
               800000000, volt: 900000, enabled: 1. New: freq: 800000000,
               volt: 900000, enabled: 1
  rk3399-dmc-freq dmc: _opp_add: duplicate OPPs detected. Existing: freq:
               928000000, volt: 900000, enabled: 1. New: freq: 928000000,
               volt: 900000, enabled: 1

This patch fixes the error path in the probe function and adds a .remove
function to properly cleanup the opp table on unloading.

Fixes: 5a893e31a636c (PM / devfreq: rockchip: add devfreq driver for rk3399 dmc)
Signed-off-by: Enric Balletbo i Serra <redacted>
---

 drivers/devfreq/rk3399_dmc.c | 31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/drivers/devfreq/rk3399_dmc.c b/drivers/devfreq/rk3399_dmc.c
index d5c03e5abe13..e795ad2b3f6b 100644
--- a/drivers/devfreq/rk3399_dmc.c
+++ b/drivers/devfreq/rk3399_dmc.c

@@ -375,8 +375,10 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev)
        data->rate = clk_get_rate(data->dmc_clk);

        opp = devfreq_recommended_opp(dev, &data->rate, 0);
-       if (IS_ERR(opp))
-               return PTR_ERR(opp);
+       if (IS_ERR(opp)) {
+               ret = PTR_ERR(opp);
+               goto err_free_opp;
+       }

        data->rate = dev_pm_opp_get_freq(opp);
        data->volt = dev_pm_opp_get_voltage(opp);

@@ -388,13 +390,33 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev)
                                           &rk3399_devfreq_dmc_profile,
                                           DEVFREQ_GOV_SIMPLE_ONDEMAND,
                                           &data->ondemand_data);
-       if (IS_ERR(data->devfreq))
-               return PTR_ERR(data->devfreq);
+       if (IS_ERR(data->devfreq)) {
+               ret = PTR_ERR(data->devfreq);
+               goto err_free_opp;
+       }
+
        devm_devfreq_register_opp_notifier(dev, data->devfreq);

        data->dev = dev;
        platform_set_drvdata(pdev, data);

+       return 0;

It looks strange. Because rk3399_dmcfreq_probe() already include
'return 0' when success.
What is the base commit of this patch?

Sorry, I am not sure I understand your question, If I am not answering
below could you rephrase?

When I check the rk3399_dmcfreq_probe()[1], as I commented,
rk3399_dmcfreq_probe() already 'return 0' after platform_set_drvdata().
You can check it on link[1].
[1] https://elixir.bootlin.com/linux/v4.18-rc1/source/drivers/devfreq/rk3399_dmc.c#L443

But, this patch add new '+       return 0;' line again in rk3399_dmcfreq_probe().
So, just I asked what is base commit of this patch.

So, once the opp table is added we need an error path to free it if an
error occurs later. When the probe returns 0, we need to free the opp
table when we remove the module.

quoted

[snip]

Anyway, if probe fail, device driver have to remove registered OPP table.
Looks good to me.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>

Thanks,
 Enric

quoted

--
Best Regards,
Chanwoo Choi
Samsung Electronics

-- 
Best Regards,
Chanwoo Choi
Samsung Electronics