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* [PATCH] cleanup LED documentation and make it match reality
@ 2016-10-03  8:10 ` Pavel Machek
  2016-10-03  8:20   ` Greg KH
  2016-10-03  9:27   ` Jacek Anaszewski
  0 siblings, 2 replies; 6+ messages in thread
From: Pavel Machek @ 2016-10-03  8:10 UTC (permalink / raw)
  To: j.anaszewski, linux-leds, kernel list, Greg KH

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sysfs-class-led fails to mention some important details. Also fix led
vs LED and english.

Signed-off-by: Pavel Machek <pavel@ucw.cz>

--- a/Documentation/ABI/testing/sysfs-class-led
+++ b/Documentation/ABI/testing/sysfs-class-led
@@ -4,16 +4,25 @@ KernelVersion:	2.6.17
 Contact:	Richard Purdie <rpurdie@rpsys.net>
 Description:
 		Set the brightness of the LED. Most LEDs don't
-		have hardware brightness support so will just be turned on for
+		have hardware brightness support, so will just be turned on for
 		non-zero brightness settings. The value is between 0 and
 		/sys/class/leds/<led>/max_brightness.
 
+		Writing 0 to this file clears active trigger.
+
+		Writing non-zero to this file while trigger is active changes the
+		top brightness trigger is going to use.
+		
+
 What:		/sys/class/leds/<led>/max_brightness
 Date:		March 2006
 KernelVersion:	2.6.17
 Contact:	Richard Purdie <rpurdie@rpsys.net>
 Description:
-		Maximum brightness level for this led, default is 255 (LED_FULL).
+		Maximum brightness level for this LED, default is 255 (LED_FULL).
+
+		If the LED does not support different brightness levels, this
+		should be 1.
 
 What:		/sys/class/leds/<led>/trigger
 Date:		March 2006
@@ -21,7 +30,7 @@ KernelVersion:	2.6.17
 Contact:	Richard Purdie <rpurdie@rpsys.net>
 Description:
 		Set the trigger for this LED. A trigger is a kernel based source
-		of led events.
+		of LED events.
 		You can change triggers in a similar manner to the way an IO
 		scheduler is chosen. Trigger specific parameters can appear in
 		/sys/class/leds/<led> once a given trigger is selected.

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] cleanup LED documentation and make it match reality
  2016-10-03  8:10 ` [PATCH] cleanup LED documentation and make it match reality Pavel Machek
@ 2016-10-03  8:20   ` Greg KH
  2016-10-03  9:27   ` Jacek Anaszewski
  1 sibling, 0 replies; 6+ messages in thread
From: Greg KH @ 2016-10-03  8:20 UTC (permalink / raw)
  To: Pavel Machek; +Cc: j.anaszewski, linux-leds, kernel list

On Mon, Oct 03, 2016 at 10:10:50AM +0200, Pavel Machek wrote:
> 
> sysfs-class-led fails to mention some important details. Also fix led
> vs LED and english.
> 
> Signed-off-by: Pavel Machek <pavel@ucw.cz>
> 
> --- a/Documentation/ABI/testing/sysfs-class-led
> +++ b/Documentation/ABI/testing/sysfs-class-led
> @@ -4,16 +4,25 @@ KernelVersion:	2.6.17
>  Contact:	Richard Purdie <rpurdie@rpsys.net>
>  Description:
>  		Set the brightness of the LED. Most LEDs don't
> -		have hardware brightness support so will just be turned on for
> +		have hardware brightness support, so will just be turned on for
>  		non-zero brightness settings. The value is between 0 and
>  		/sys/class/leds/<led>/max_brightness.
>  
> +		Writing 0 to this file clears active trigger.
> +
> +		Writing non-zero to this file while trigger is active changes the
> +		top brightness trigger is going to use.
> +		

No trailing whitespace please...

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] cleanup LED documentation and make it match reality
  2016-10-03  8:10 ` [PATCH] cleanup LED documentation and make it match reality Pavel Machek
  2016-10-03  8:20   ` Greg KH
@ 2016-10-03  9:27   ` Jacek Anaszewski
  2016-10-03  9:38     ` Pavel Machek
  1 sibling, 1 reply; 6+ messages in thread
From: Jacek Anaszewski @ 2016-10-03  9:27 UTC (permalink / raw)
  To: Pavel Machek, linux-leds, kernel list, Greg KH

Hi Pavel,

Thanks for the patch.

On 10/03/2016 10:10 AM, Pavel Machek wrote:
>
> sysfs-class-led fails to mention some important details. Also fix led
> vs LED and english.
>
> Signed-off-by: Pavel Machek <pavel@ucw.cz>
>
> --- a/Documentation/ABI/testing/sysfs-class-led
> +++ b/Documentation/ABI/testing/sysfs-class-led
> @@ -4,16 +4,25 @@ KernelVersion:	2.6.17
>  Contact:	Richard Purdie <rpurdie@rpsys.net>
>  Description:
>  		Set the brightness of the LED. Most LEDs don't
> -		have hardware brightness support so will just be turned on for
> +		have hardware brightness support, so will just be turned on for
>  		non-zero brightness settings. The value is between 0 and
>  		/sys/class/leds/<led>/max_brightness.
>
> +		Writing 0 to this file clears active trigger.
> +
> +		Writing non-zero to this file while trigger is active changes the
> +		top brightness trigger is going to use.

This is true only in case of timer trigger, as it uses blink_brightness
property from struct led_classdev to cache current brightness, when the
the LED is in the off cycle. This is part of software blink fallback
functionality.

In case of heartbeat trigger max_brightness is always used for top level
brightness. We'd need to refactor the trigger a bit to allow for
different top brightness levels.

> +		
> +
>  What:		/sys/class/leds/<led>/max_brightness
>  Date:		March 2006
>  KernelVersion:	2.6.17
>  Contact:	Richard Purdie <rpurdie@rpsys.net>
>  Description:
> -		Maximum brightness level for this led, default is 255 (LED_FULL).
> +		Maximum brightness level for this LED, default is 255 (LED_FULL).
> +
> +		If the LED does not support different brightness levels, this
> +		should be 1.
>
>  What:		/sys/class/leds/<led>/trigger
>  Date:		March 2006
> @@ -21,7 +30,7 @@ KernelVersion:	2.6.17
>  Contact:	Richard Purdie <rpurdie@rpsys.net>
>  Description:
>  		Set the trigger for this LED. A trigger is a kernel based source
> -		of led events.
> +		of LED events.
>  		You can change triggers in a similar manner to the way an IO
>  		scheduler is chosen. Trigger specific parameters can appear in
>  		/sys/class/leds/<led> once a given trigger is selected.
>


-- 
Best regards,
Jacek Anaszewski

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] cleanup LED documentation and make it match reality
  2016-10-03  9:27   ` Jacek Anaszewski
@ 2016-10-03  9:38     ` Pavel Machek
  2016-10-03  9:54       ` Jacek Anaszewski
  2016-10-19  8:46       ` Jacek Anaszewski
  0 siblings, 2 replies; 6+ messages in thread
From: Pavel Machek @ 2016-10-03  9:38 UTC (permalink / raw)
  To: Jacek Anaszewski; +Cc: linux-leds, kernel list, Greg KH

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Hi!

> Thanks for the patch.
> 
> On 10/03/2016 10:10 AM, Pavel Machek wrote:
> >
> >sysfs-class-led fails to mention some important details. Also fix led
> >vs LED and english.
> >
> >Signed-off-by: Pavel Machek <pavel@ucw.cz>
> >
> >--- a/Documentation/ABI/testing/sysfs-class-led
> >+++ b/Documentation/ABI/testing/sysfs-class-led
> >@@ -4,16 +4,25 @@ KernelVersion:	2.6.17
> > Contact:	Richard Purdie <rpurdie@rpsys.net>
> > Description:
> > 		Set the brightness of the LED. Most LEDs don't
> >-		have hardware brightness support so will just be turned on for
> >+		have hardware brightness support, so will just be turned on for
> > 		non-zero brightness settings. The value is between 0 and
> > 		/sys/class/leds/<led>/max_brightness.
> >
> >+		Writing 0 to this file clears active trigger.
> >+
> >+		Writing non-zero to this file while trigger is active changes the
> >+		top brightness trigger is going to use.
> 
> This is true only in case of timer trigger, as it uses blink_brightness
> property from struct led_classdev to cache current brightness, when the
> the LED is in the off cycle. This is part of software blink fallback
> functionality.
> 
> In case of heartbeat trigger max_brightness is always used for top level
> brightness. We'd need to refactor the trigger a bit to allow for
> different top brightness levels.

Ok, do you think you could update the documenation to match the
reality? It is quite important to know what is the intended behaviour
and what are the bugs.

Thanks,
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] cleanup LED documentation and make it match reality
  2016-10-03  9:38     ` Pavel Machek
@ 2016-10-03  9:54       ` Jacek Anaszewski
  2016-10-19  8:46       ` Jacek Anaszewski
  1 sibling, 0 replies; 6+ messages in thread
From: Jacek Anaszewski @ 2016-10-03  9:54 UTC (permalink / raw)
  To: Pavel Machek; +Cc: linux-leds, kernel list, Greg KH

On 10/03/2016 11:38 AM, Pavel Machek wrote:
> Hi!
>
>> Thanks for the patch.
>>
>> On 10/03/2016 10:10 AM, Pavel Machek wrote:
>>>
>>> sysfs-class-led fails to mention some important details. Also fix led
>>> vs LED and english.
>>>
>>> Signed-off-by: Pavel Machek <pavel@ucw.cz>
>>>
>>> --- a/Documentation/ABI/testing/sysfs-class-led
>>> +++ b/Documentation/ABI/testing/sysfs-class-led
>>> @@ -4,16 +4,25 @@ KernelVersion:	2.6.17
>>> Contact:	Richard Purdie <rpurdie@rpsys.net>
>>> Description:
>>> 		Set the brightness of the LED. Most LEDs don't
>>> -		have hardware brightness support so will just be turned on for
>>> +		have hardware brightness support, so will just be turned on for
>>> 		non-zero brightness settings. The value is between 0 and
>>> 		/sys/class/leds/<led>/max_brightness.
>>>
>>> +		Writing 0 to this file clears active trigger.
>>> +
>>> +		Writing non-zero to this file while trigger is active changes the
>>> +		top brightness trigger is going to use.
>>
>> This is true only in case of timer trigger, as it uses blink_brightness
>> property from struct led_classdev to cache current brightness, when the
>> the LED is in the off cycle. This is part of software blink fallback
>> functionality.
>>
>> In case of heartbeat trigger max_brightness is always used for top level
>> brightness. We'd need to refactor the trigger a bit to allow for
>> different top brightness levels.
>
> Ok, do you think you could update the documenation to match the
> reality? It is quite important to know what is the intended behaviour
> and what are the bugs.

I'd prefer to improve the trigger. I'll try to do that in the coming
days, and apply your patch afterwards.

-- 
Best regards,
Jacek Anaszewski

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] cleanup LED documentation and make it match reality
  2016-10-03  9:38     ` Pavel Machek
  2016-10-03  9:54       ` Jacek Anaszewski
@ 2016-10-19  8:46       ` Jacek Anaszewski
  1 sibling, 0 replies; 6+ messages in thread
From: Jacek Anaszewski @ 2016-10-19  8:46 UTC (permalink / raw)
  To: Pavel Machek; +Cc: linux-leds, kernel list, Greg KH

On 10/03/2016 11:38 AM, Pavel Machek wrote:
> Hi!
>
>> Thanks for the patch.
>>
>> On 10/03/2016 10:10 AM, Pavel Machek wrote:
>>>
>>> sysfs-class-led fails to mention some important details. Also fix led
>>> vs LED and english.
>>>
>>> Signed-off-by: Pavel Machek <pavel@ucw.cz>
>>>
>>> --- a/Documentation/ABI/testing/sysfs-class-led
>>> +++ b/Documentation/ABI/testing/sysfs-class-led
>>> @@ -4,16 +4,25 @@ KernelVersion:	2.6.17
>>> Contact:	Richard Purdie <rpurdie@rpsys.net>
>>> Description:
>>> 		Set the brightness of the LED. Most LEDs don't
>>> -		have hardware brightness support so will just be turned on for
>>> +		have hardware brightness support, so will just be turned on for
>>> 		non-zero brightness settings. The value is between 0 and
>>> 		/sys/class/leds/<led>/max_brightness.
>>>
>>> +		Writing 0 to this file clears active trigger.
>>> +
>>> +		Writing non-zero to this file while trigger is active changes the
>>> +		top brightness trigger is going to use.
>>
>> This is true only in case of timer trigger, as it uses blink_brightness
>> property from struct led_classdev to cache current brightness, when the
>> the LED is in the off cycle. This is part of software blink fallback
>> functionality.
>>
>> In case of heartbeat trigger max_brightness is always used for top level
>> brightness. We'd need to refactor the trigger a bit to allow for
>> different top brightness levels.
>
> Ok, do you think you could update the documenation to match the
> reality? It is quite important to know what is the intended behaviour
> and what are the bugs.

Applied the patch (removed extra empty line) after improving heartbeat
trigger [0] to support brightness levels other then max_brightness.

[0] 
https://git.kernel.org/cgit/linux/kernel/git/j.anaszewski/linux-leds.git/commit/?h=for-next&id=9a1d1e6f926a4d1f4a31a7a37abece9e44455b43

-- 
Best regards,
Jacek Anaszewski

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2016-10-19 14:56 UTC | newest]

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2016-10-03  8:10 ` [PATCH] cleanup LED documentation and make it match reality Pavel Machek
2016-10-03  8:20   ` Greg KH
2016-10-03  9:27   ` Jacek Anaszewski
2016-10-03  9:38     ` Pavel Machek
2016-10-03  9:54       ` Jacek Anaszewski
2016-10-19  8:46       ` Jacek Anaszewski

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