linux-kernel - Re: [PATCH 4/5] leds: core: Add an internal led_set_brightness

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Date:	Wed, 23 Sep 2015 10:53:49 +0200
From:	Jacek Anaszewski <j.anaszewski@...sung.com>
To:	Andrew Lunn <andrew@...n.ch>
Cc:	linux-leds@...r.kernel.org, linux-kernel@...r.kernel.org,
	sakari.ailus@...ux.intel.com, stsp@...rs.sourceforge.net,
	pavel@....cz, ospite@...denti.unina.it, davem@...emloft.net,
	linus.walleij@...aro.org, ricardo.ribalda@...il.com,
	p.meerwald@...-electronic.com
Subject: Re: [PATCH 4/5] leds: core: Add an internal led_set_brightness_nosleep
 function

On 09/22/2015 09:02 PM, Andrew Lunn wrote:
>> +void led_set_brightness_nosleep(struct led_classdev *led_cdev,
>> +					enum led_brightness value)
>> +{
>> +	led_cdev->brightness = min(value, led_cdev->max_brightness);
>> +
>> +	if (led_cdev->flags & LED_SUSPENDED)
>> +		return;
>> +
>> +	/* Use brightness_set op if available, it is guaranteed not to sleep */
>> +	if (led_cdev->brightness_set)
>> +		led_cdev->brightness_set(led_cdev, led_cdev->brightness);
>> +
>> +	/* If brightness setting can sleep, delegate it to a work queue task */
>> +	led_cdev->delayed_set_value = led_cdev->brightness;
>> +	schedule_work(&led_cdev->set_brightness_work);
>> +}
>
> To me, it looks like there is a missing else, or return here. We don't
> want both led_cdev->brightness_set() and the work queue.

Thanks for spotting this.

>> +EXPORT_SYMBOL(led_set_brightness_nosleep);
>
> There seems to be a mixture of EXPORT_SYMBOL and
> EXPORT_SYMBOL_GPL. Have you figured out the pattern? led-class.c seems
> to be all _GPL, but led-core.c has a mixture.

In fact, this is weird. I didn't pay sufficient attention to this,
I must admit. We should switch to using EXPORT_SYMBOL_GPL consequently [1].

[1] https://lwn.net/Articles/603187/

-- 
Best Regards,
Jacek Anaszewski
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