Re: [PATCH v7 08/13] leds: trigger: netdev: Implement hw_offloaded() callback

[Lee Jones <lee@kernel.org>]

--- checkpatch.pl: clean (0 issues) ---

On Mon, 21 Sep 2026, Rong Zhang wrote:

> "netdev" can run in hardware control according to hardware capabilities
> and trigger options.
> 
> Implement hw_offloaded() callback to provide its hardware control state
> to the LED core, and document the relation between the custom
> "offloaded" attribute and the generic "trigger_may_offload_to_hw"
> attribute.
> 
> The callback mimics how the existing "offloaded" attribute does, i.e.,
> locklessly reads hw_control, as it's just a hint and don't need to be
> accurate.
> 
> Acked-by: Ike Panhc <ikepanhc@gmail.com>
> Signed-off-by: Rong Zhang <i@rong.moe>
> ---
> Changes in v7:
> - Rename the offloaded() callback to hw_offloaded() (thanks Lee Jones)
> - Rename the trigger_may_offload attribute to
>   trigger_may_offload_to_hw (ditto)
> 
> Changes in v3:
> - Do not deprecate netdev's "offloaded" attribute (thanks Thomas
>   Weißschuh)
> - Document the relation between the custom "offloaded" attribute and the
>   generic "trigger_may_offload" attribute (ditto)
> ---
>  Documentation/ABI/testing/sysfs-class-led                | 3 +++
>  Documentation/ABI/testing/sysfs-class-led-trigger-netdev | 3 +++
>  drivers/leds/trigger/ledtrig-netdev.c                    | 8 ++++++++
>  3 files changed, 14 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-class-led b/Documentation/ABI/testing/sysfs-class-led
> index 123e3a15b7d6..ea113fed10ef 100644
> --- a/Documentation/ABI/testing/sysfs-class-led
> +++ b/Documentation/ABI/testing/sysfs-class-led
> @@ -101,6 +101,9 @@ Description:
>  		- `[foo_trigger]`: the trigger is selected and offloaded to
>  		  hardware.
>  
> +		The "netdev" trigger also provides a custom attribute to
> +		indicate its state, see `/sys/class/leds/<led>/offloaded`.
> +
>  What:		/sys/class/leds/<led>/inverted
>  Date:		January 2011
>  KernelVersion:	2.6.38
> diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-netdev b/Documentation/ABI/testing/sysfs-class-led-trigger-netdev
> index ed46b37ab8a2..203ea58396ed 100644
> --- a/Documentation/ABI/testing/sysfs-class-led-trigger-netdev
> +++ b/Documentation/ABI/testing/sysfs-class-led-trigger-netdev
> @@ -75,6 +75,9 @@ Description:
>  		If 1, the LED blinking in requested mode is offloaded to
>  		hardware.
>  
> +		LED trigger core also provides a generic attribute for this
> +		purpose, see `/sys/class/leds/<led>/trigger_may_offload_to_hw`.
> +
>  What:		/sys/class/leds/<led>/link_10
>  Date:		Jun 2023
>  KernelVersion:	6.5
> diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c
> index 5b4e92c14dbb..60409f054e22 100644
> --- a/drivers/leds/trigger/ledtrig-netdev.c
> +++ b/drivers/leds/trigger/ledtrig-netdev.c
> @@ -798,10 +798,18 @@ static void netdev_trig_deactivate(struct led_classdev *led_cdev)
>  	kfree(trigger_data);
>  }
>  
> +static bool netdev_trig_hw_offloaded(struct led_classdev *led_cdev)
> +{
> +	struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
> +
> +	return trigger_data->hw_control;

How sure are we that trigger_data can NEVER be NULL?

> +}
> +
>  static struct led_trigger netdev_led_trigger = {
>  	.name = "netdev",
>  	.activate = netdev_trig_activate,
>  	.deactivate = netdev_trig_deactivate,
> +	.hw_offloaded = netdev_trig_hw_offloaded,
>  	.groups = netdev_trig_groups,
>  };
>  
> 
> -- 
> 2.55.0
> 

-- 
Lee Jones