Re: [PATCH] led: ledtrig-transient: replace timer_list with hrtimer

From: Jacek Anaszewski
Date: Thu Apr 27 2017 - 14:38:17 EST


On 04/27/2017 05:48 AM, David Lin wrote:
> On Tue, Apr 25, 2017 at 1:15 PM, Jacek Anaszewski
> <jacek.anaszewski@xxxxxxxxx> wrote:
>>> However, there's a need to
>>> support hrtimer if the LED subsystem claims support the use case of
>>> vibrator (please see Documentation/leds/ledtrig-transient.txt) as even
>>> a 5ms of variation is perceivable to the user. I'm thinking if a
>>> better interim solution is to introduce a
>>> LEDS_TRIGGER_TRANSIENT_HRTIMER config to work with both timers in
>>> compile time. Would you agree?
>>
>> I think that it would be better if LED class driver set a flag
>> marking itself as capable of setting brightness with high rate.
>> I'd limit that only to leds-gpio and devices driven through
>> memory mapped registers.
>>
>> Having the flag e.g. LED_BRIGHTNESS_FAST, we could add support for
>> hr timers also to ledtrig-timer.
>
> Can I resubmit the patch implementing LED_BRIGHTNESS_FAST using hrtimer?

Yeah, but please split the changes into two patches:

1/2 - addition of a flag to linux/leds.h and corresponding update of
Documentation/leds/leds-class.txt
2/2 - addition of hr timer support to ledtrig-transient.c

--
Best regards,
Jacek Anaszewski