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Subject: Re: [PATCH v3 2/2] PM / devfreq: Add governor attribute flag for
 specifc sysfs nodes
From:   Chanwoo Choi <cw00.choi@samsung.com>
To:     Dmitry Osipenko <digetx@gmail.com>, linux-pm@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org
Cc:     leonard.crestez@nxp.com, lukasz.luba@arm.com,
        enric.balletbo@collabora.com, hl@rock-chips.com,
        thierry.reding@gmail.com, jonathanh@nvidia.com, abel.vesa@nxp.com,
        k.konieczny@samsung.com, b.zolnierkie@samsung.com,
        chanwoo@kernel.org, myungjoo.ham@samsung.com,
        kyungmin.park@samsung.com
Organization: Samsung Electronics
Message-ID: <d198e358-f636-2f52-1d73-098f8bebffbf@samsung.com>
Date:   Mon, 19 Oct 2020 19:41:01 +0900
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On 10/19/20 1:11 PM, Chanwoo Choi wrote:
> On 10/19/20 9:39 AM, Dmitry Osipenko wrote:
>> ...
>>> @@ -1361,6 +1373,9 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
>>>  		goto out;
>>>  	}
>>>  
>>> +	remove_sysfs_files(df, df->governor);
>>> +	create_sysfs_files(df, governor);
>>> +
>>>  	prev_governor = df->governor;
>>>  	df->governor = governor;
>>>  	strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN);
>>> @@ -1460,39 +1475,6 @@ static ssize_t target_freq_show(struct device *dev,
>>>  }
>>
>> The further code may revert df->governor to the prev_governor or set it
> 
> prev_governor is better. I'll change it.
> 
>> to NULL. The create_sysfs_files(df->governor) should be invoked at the

Also, when creating and removing the sysfs files, devfreq instance is needed
because of df->dev.kobj. So, *_sysfs_files need the two parameters.

>> very end of the governor_store() and only in a case of success.
> 
> OK. I'll add more exception handling code.
> 
> 


-- 
Best Regards,
Chanwoo Choi
Samsung Electronics