Messages in this thread | | | Subject | Re: [PATCH] LEDS-One-Shot-Timer-Trigger-implementation | From | Shuah Khan <> | Date | Wed, 28 Mar 2012 10:09:09 -0600 |
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Neil,
> > In general I approve of this - thanks for your efforts. > > However there are some details that need attention.
Thanks. > > > > > This patch implements the one-shot-timer trigger support by enhancing the > > current led-class and ledtrig-timer drivers to support the following > > use-cases: > > > > use-case 1: > > echo one-shot-timer > /sys/class/leds/SOMELED/trigger > > I don't like the name "one-shot-timer". This name describes how you expect > the functionality to be used, but not what the actual difference between > "timer" and "one-shot-timer" is. > That difference is simply that one-shot-timer does not start an initial > default blink, while "timer" does. > So a name like "timer-no-default" would be a more accurate description and so > should be preferred.
Yes, timer-no-default describes the enhancement I am making, better than one-shot-timer does. I will generate patch v2 to address your concerns and will change the name to timer-no-default and update the relevant code and documentation that goes with the patch to reflect the change. > > > > echo 2000 > /sys/class/leds/SOMELED/delay_on > > This command will call led_blink_set with an on time of '2000' and an off > time of '0'. This will cause led_set_software_blink to turn the LED on and > set no off timer. This is just as bad as starting a default blink - there is > no guarantee that the LED (or vibrator) will ever be turned off. > > You need to set 'delay_off' to 'forever' first.
Good point. Will update the documentation. > > > > I think you should also mention here that: > > - The 'forever' value is stored as 'ULONG_MAX'. Possibly a > #define FOREVER ULONG_MAX > in the code would be appropriate. This mapping is only used internally, > not in the interface. > > - The led_blink_set function - which takes two pointers to times - has > been extended so that a NULL instead of a pointer means "forever".
Will do.
> > + > > I think > return sprintf(buf, "forever\n"); > > if the more common usage. > > Also in led_delay_off_show() below.
ok. >
> > kstrtoul is currently preferred. It ensures uniform error codes. >
Yes. I noticed the checkpatch.pl warnings. This change is better made as a separate patch. Do you mind if I deferred it and volunteer to fix it in a separate patch shortly. :)
> > > + > > Do you need to led_trigger_unregister(&timer_led_trigger) if the registration > of one_shot_timer_led_trigger fails?
Yes, considered that while I was changing this routine, and thought might be better to leave the registered timer alone when the second registration fails. I can go either way.
-- Shuah
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