linux-kernel - Re: [PATCH] leds: remove redundant SET_BRIGHTNESS

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Date:	Thu, 14 May 2015 11:19:00 +0200
From:	Jacek Anaszewski <j.anaszewski@...sung.com>
To:	Stas Sergeev <stsp@...t.ru>
Cc:	linux-leds@...r.kernel.org,
	Linux kernel <linux-kernel@...r.kernel.org>,
	Bryan Wu <cooloney@...il.com>,
	Richard Purdie <rpurdie@...ys.net>,
	Stas Sergeev <stsp@...rs.sourceforge.net>
Subject: Re: [PATCH] leds: remove redundant SET_BRIGHTNESS_SYNC flag

On 05/14/2015 11:11 AM, Jacek Anaszewski wrote:
> I personally can't find any strong argument against this optimization.
> I added both flags on Bryan's request while implementing LED Flash class
> extension. I can see a few occurrences in the include/linux directory
> where both SYNC and ASYNC flags are implemented. The argument in favour

I meant: "in favour of keeping that as is"

> could be the fact that the flags influence the core functionality of
> the subsystem.
>
> Bryan, could you express your opinion, please?
>
> On 05/13/2015 05:41 PM, Stas Sergeev wrote:
>>
>> There is a complimentary flag called SET_BRIGHTNESS_ASYNC.
>> Having both is redundant. This patch removes the unneeded flag
>> without any functionality change.
>>
>> CC: Bryan Wu <cooloney@...il.com>
>> CC: Richard Purdie <rpurdie@...ys.net>
>> CC: linux-leds@...r.kernel.org
>> CC: linux-kernel@...r.kernel.org
>>
>> Signed-off-by: Stas Sergeev <stsp@...rs.sourceforge.net>
>> ---
>>   drivers/leds/led-class-flash.c |    1 -
>>   drivers/leds/led-core.c        |    4 +---
>>   include/linux/leds.h           |    2 +-
>>   3 files changed, 2 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/leds/led-class-flash.c
>> b/drivers/leds/led-class-flash.c
>> index 3b25734..bb67364 100644
>> --- a/drivers/leds/led-class-flash.c
>> +++ b/drivers/leds/led-class-flash.c
>> @@ -318,7 +318,6 @@ int led_classdev_flash_register(struct device
>> *parent,
>>
>>       /* Setting a torch brightness needs to have immediate effect */
>>       led_cdev->flags &= ~SET_BRIGHTNESS_ASYNC;
>> -    led_cdev->flags |= SET_BRIGHTNESS_SYNC;
>>
>>       return 0;
>>   }
>> diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
>> index 9886dac..356e851 100644
>> --- a/drivers/leds/led-core.c
>> +++ b/drivers/leds/led-core.c
>> @@ -129,10 +129,8 @@ void led_set_brightness(struct led_classdev
>> *led_cdev,
>>       if (led_cdev->flags & SET_BRIGHTNESS_ASYNC) {
>>           led_set_brightness_async(led_cdev, brightness);
>>           return;
>> -    } else if (led_cdev->flags & SET_BRIGHTNESS_SYNC)
>> +    } else
>>           ret = led_set_brightness_sync(led_cdev, brightness);
>> -    else
>> -        ret = -EINVAL;
>>
>>       if (ret < 0)
>>           dev_dbg(led_cdev->dev, "Setting LED brightness failed (%d)\n",
>> diff --git a/include/linux/leds.h b/include/linux/leds.h
>> index 9a2b000..c9e6e5d 100644
>> --- a/include/linux/leds.h
>> +++ b/include/linux/leds.h
>> @@ -45,7 +45,7 @@ struct led_classdev {
>>   #define LED_BLINK_INVERT    (1 << 19)
>>   #define LED_SYSFS_DISABLE    (1 << 20)
>>   #define SET_BRIGHTNESS_ASYNC    (1 << 21)
>> -#define SET_BRIGHTNESS_SYNC    (1 << 22)
>> +/* bit 22 unused, take it */
>>   #define LED_DEV_CAP_FLASH    (1 << 23)
>>
>>       /* Set LED brightness level */
>>
>
>


-- 
Best Regards,
Jacek Anaszewski
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