Re: [PATCH v7 1/5] leds: flash: Add flash registration with undefined CONFIG_LEDS_CLASS_FLASH

Jacek Anaszewski
2020-11-23T21:07:11Z

On 11/23/20 4:20 AM, Gene Chen wrote:
> Jacek Anaszewski <jacek.anaszewski@gmail.com> 於 2020年11月20日 週五 上午6:29寫道：
>>
>> Hi Gene,
>>
>> On 11/18/20 11:47 AM, Gene Chen wrote:
>>> From: Gene Chen <gene_chen@richtek.com>
>>>
>>> Add flash registration with undefined CONFIG_LEDS_CLASS_FLASH
>>>
>>> Signed-off-by: Gene Chen <gene_chen@richtek.com>
>>> ---
>>> include/linux/led-class-flash.h | 36 ++++++++++++++++++++++++++++++++++++
>>> 1 file changed, 36 insertions(+)
>>>
>>> diff --git a/include/linux/led-class-flash.h b/include/linux/led-class-flash.h
>>> index 21a3358..4f56c28 100644
>>> --- a/include/linux/led-class-flash.h
>>> +++ b/include/linux/led-class-flash.h
>>> @@ -85,6 +85,7 @@ static inline struct led_classdev_flash *lcdev_to_flcdev(
>>> return container_of(lcdev, struct led_classdev_flash, led_cdev);
>>> }
>>>
>>> +#if IS_ENABLED(CONFIG_LEDS_CLASS_FLASH)
>>> /**
>>> * led_classdev_flash_register_ext - register a new object of LED class with
>>> * init data and with support for flash LEDs
>>> @@ -127,6 +128,41 @@ static inline int devm_led_classdev_flash_register(struct device *parent,
>>> void devm_led_classdev_flash_unregister(struct device *parent,
>>> struct led_classdev_flash *fled_cdev);
>>>
>>> +#else
>>> +
>>> +static inline int led_classdev_flash_register_ext(struct device *parent,
>>> + struct led_classdev_flash *fled_cdev,
>>> + struct led_init_data *init_data)
>>> +{
>>> + return -EINVAL;
>>
>> s/-EINVAL/0/
>>
>> The goal here is to assure that client will not fail when using no-op.
>>
>>> +}
>>> +
>>> +static inline int led_classdev_flash_register(struct device *parent,
>>> + struct led_classdev_flash *fled_cdev)
>>> +{
>>> + return led_classdev_flash_register_ext(parent, fled_cdev, NULL);
>>> +}
>>
>> This function should be placed after #ifdef block because its
>> shape is the same for both cases.
>>
>>> +static inline void led_classdev_flash_unregister(struct led_classdev_flash *fled_cdev) {};
>>> +static inline int devm_led_classdev_flash_register_ext(struct device *parent,
>>> + struct led_classdev_flash *fled_cdev,
>>> + struct led_init_data *init_data)
>>> +{
>>> + return -EINVAL;
>>
>> /-EINVAL/0/
>>
>> Please do the same fix in all no-ops in the led-class-multicolor.h,
>> as we've discussed.
>>
>
> I think return -EINVAL is correct, because I should register flash
> light device if I define FLED in DTS node.

I don't quite follow your logic here.

No-op function's purpose is to simplify the code on the caller's side.
Therefore it should report success.

Please return 0 from it.

--
Best regards,
Jacek Anaszewski