Re: [PATCH/RFC v2] leds: trigger: Introduce a NETDEV trigger

From: Jacek Anaszewski
Date: Tue Dec 05 2017 - 15:39:36 EST


Hi Ben,

On 12/05/2017 12:19 PM, Ben Whitten wrote:
> From: Ben Whitten <ben.whitten@xxxxxxxxx>
>
> The patch was converted to led_blink_oneshot, in doing so we find that the
> behaviour has changed. As I dont want to break 'userspace' led behaviour this
> patch shouldn't be merged as is. Open to suggestions.
>
> Given an interval of 50ms and heavy throughput, the previous implementation
> produced a blink with 100ms period and 50% dutycycle. The led_blink_oneshot
> version produces a blink with 140ms period and 57% dutycycle.

Please check if the LED class driver you're testing the trigger with
implements blink_set op. If yes it would be good to check if it doesn't
align the delay intervals to the hardware capabilities instead of
failing and relying on a LED core software blink fallback.


> I assume a fudge factor on the oneshot delay to bring the period back to 100ms
> would be device specific so not suitable.
>
> Kind regards,
> Ben Whitten (1):
> leds: trigger: Introduce a NETDEV trigger
>
> .../ABI/testing/sysfs-class-led-trigger-netdev | 45 ++
> drivers/leds/trigger/Kconfig | 7 +
> drivers/leds/trigger/Makefile | 1 +
> drivers/leds/trigger/ledtrig-netdev.c | 507 +++++++++++++++++++++
> 4 files changed, 560 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-class-led-trigger-netdev
> create mode 100644 drivers/leds/trigger/ledtrig-netdev.c
>

--
Best regards,
Jacek Anaszewski