[4/5] devicetree: leds: Introduce "panic-blink" optional property
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Message ID 1459801326-5541-5-git-send-email-ezequiel@vanguardiasur.com.ar
State New, archived
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Series
  • Extend the LED panic trigger
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Commit Message

Ezequiel Garcia April 4, 2016, 8:22 p.m. UTC
It's desirable to specify which LEDs are to be blinked on a kernel
panic. Therefore, introduce a devicetree boolean property to mark
which LEDs should be treated this way.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
---
 Documentation/devicetree/bindings/leds/common.txt | 2 ++
 1 file changed, 2 insertions(+)

Comments

Jacek Anaszewski April 5, 2016, 9:37 p.m. UTC | #1
Hi Ezequiel,

On 04/04/2016 10:22 PM, Ezequiel Garcia wrote:
> It's desirable to specify which LEDs are to be blinked on a kernel
> panic. Therefore, introduce a devicetree boolean property to mark
> which LEDs should be treated this way.
>
> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
> ---
>   Documentation/devicetree/bindings/leds/common.txt | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/leds/common.txt b/Documentation/devicetree/bindings/leds/common.txt
> index 68419843e32f..dd409df9203a 100644
> --- a/Documentation/devicetree/bindings/leds/common.txt
> +++ b/Documentation/devicetree/bindings/leds/common.txt
> @@ -37,6 +37,8 @@ Optional properties for child nodes:
>                        property is mandatory for the LEDs in the non-flash modes
>                        (e.g. torch or indicator).
>
> +- panic-blink : Mark this LED to be used by the panic LED trigger.

I'd say that 'panic-indicator' would be more informative.

Please next time cc also devicetree list and maintainers.

> +
>   Required properties for flash LED child nodes:
>   - flash-max-microamp : Maximum flash LED supply current in microamperes.
>   - flash-max-timeout-us : Maximum timeout in microseconds after which the flash
>
Ezequiel Garcia April 6, 2016, 4:39 a.m. UTC | #2
On 5 April 2016 at 18:37, Jacek Anaszewski <jacek.anaszewski@gmail.com> wrote:
> Hi Ezequiel,
>
> On 04/04/2016 10:22 PM, Ezequiel Garcia wrote:
>>
>> It's desirable to specify which LEDs are to be blinked on a kernel
>> panic. Therefore, introduce a devicetree boolean property to mark
>> which LEDs should be treated this way.
>>
>> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
>> ---
>>   Documentation/devicetree/bindings/leds/common.txt | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/leds/common.txt
>> b/Documentation/devicetree/bindings/leds/common.txt
>> index 68419843e32f..dd409df9203a 100644
>> --- a/Documentation/devicetree/bindings/leds/common.txt
>> +++ b/Documentation/devicetree/bindings/leds/common.txt
>> @@ -37,6 +37,8 @@ Optional properties for child nodes:
>>                        property is mandatory for the LEDs in the non-flash
>> modes
>>                        (e.g. torch or indicator).
>>
>> +- panic-blink : Mark this LED to be used by the panic LED trigger.
>
>
> I'd say that 'panic-indicator' would be more informative.
>

Sure, that looks much better.

> Please next time cc also devicetree list and maintainers.
>

Will do.

Thanks for the reviews!
Rob Herring April 6, 2016, 3:12 p.m. UTC | #3
On Mon, Apr 4, 2016 at 3:22 PM, Ezequiel Garcia
<ezequiel@vanguardiasur.com.ar> wrote:
> It's desirable to specify which LEDs are to be blinked on a kernel
> panic. Therefore, introduce a devicetree boolean property to mark
> which LEDs should be treated this way.
>
> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
> ---
>  Documentation/devicetree/bindings/leds/common.txt | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/leds/common.txt b/Documentation/devicetree/bindings/leds/common.txt
> index 68419843e32f..dd409df9203a 100644
> --- a/Documentation/devicetree/bindings/leds/common.txt
> +++ b/Documentation/devicetree/bindings/leds/common.txt
> @@ -37,6 +37,8 @@ Optional properties for child nodes:
>                       property is mandatory for the LEDs in the non-flash modes
>                       (e.g. torch or indicator).
>
> +- panic-blink : Mark this LED to be used by the panic LED trigger.
> +

We already have a way to specify LED triggers. Why can't that be used?

Rob
Ezequiel Garcia April 6, 2016, 4:13 p.m. UTC | #4
On 6 April 2016 at 12:12, Rob Herring <robh@kernel.org> wrote:
> On Mon, Apr 4, 2016 at 3:22 PM, Ezequiel Garcia
> <ezequiel@vanguardiasur.com.ar> wrote:
>> It's desirable to specify which LEDs are to be blinked on a kernel
>> panic. Therefore, introduce a devicetree boolean property to mark
>> which LEDs should be treated this way.
>>
>> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
>> ---
>>  Documentation/devicetree/bindings/leds/common.txt | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/leds/common.txt b/Documentation/devicetree/bindings/leds/common.txt
>> index 68419843e32f..dd409df9203a 100644
>> --- a/Documentation/devicetree/bindings/leds/common.txt
>> +++ b/Documentation/devicetree/bindings/leds/common.txt
>> @@ -37,6 +37,8 @@ Optional properties for child nodes:
>>                       property is mandatory for the LEDs in the non-flash modes
>>                       (e.g. torch or indicator).
>>
>> +- panic-blink : Mark this LED to be used by the panic LED trigger.
>> +
>
> We already have a way to specify LED triggers. Why can't that be used?
>

Because this is not about specifying a LED trigger.

The use case is the following: a LED is assigned to some LED trigger.
When the kernel panics, we want to switch that LED to the panic trigger,
so it blinks signalling the panic.

IOW, this allows a LED to be used for "normal operation stuff trigger",
but blink if the kernel panics.

Patch
diff mbox series

diff --git a/Documentation/devicetree/bindings/leds/common.txt b/Documentation/devicetree/bindings/leds/common.txt
index 68419843e32f..dd409df9203a 100644
--- a/Documentation/devicetree/bindings/leds/common.txt
+++ b/Documentation/devicetree/bindings/leds/common.txt
@@ -37,6 +37,8 @@  Optional properties for child nodes:
                      property is mandatory for the LEDs in the non-flash modes
                      (e.g. torch or indicator).
 
+- panic-blink : Mark this LED to be used by the panic LED trigger.
+
 Required properties for flash LED child nodes:
 - flash-max-microamp : Maximum flash LED supply current in microamperes.
 - flash-max-timeout-us : Maximum timeout in microseconds after which the flash