On Thu, 27 May 2021 18:57:17 +0200
Andrew Lunn <andrew@xxxxxxx> wrote:
> On Wed, May 26, 2021 at 08:00:19PM +0200, Marek Behún wrote:
> > Add support for HW offloading of the netdev trigger.
> >
> > We need to export the netdev_led_trigger variable so that drivers
> > may check whether the LED is set to this trigger.
>
> Without seeing the driver side, it is not obvious to me why this is
> needed. Please add the driver changes to this patchset, so we can
> fully see how the API works.
OK, I will send an implementation for leds-turris-omnia with v2.
The idea is that the trigger_offload() method should check which
trigger it should offload. A potential LED controller may be configured
to link the LED on net activity, or on SATA activity. So the method
should do something like this:
static int my_trigger_offload(struct led_classdev *cdev, bool enable)
{
if (!enable)
return my_disable_hw_triggering(cdev);
if (cdev->trigger == &netdev_led_trigger)
return my_offload_netdev_triggering(cdev);
else if (cdev->trigger == &blkdev_led_trigger)
return my_offload_blkdev_triggering(cdev);
else
return -EOPNOTSUPP;
}
> > -static struct led_trigger netdev_led_trigger = {
> > +struct led_trigger netdev_led_trigger = {
> > .name = "netdev",
> > .activate = netdev_trig_activate,
> > .deactivate = netdev_trig_deactivate,
> > .groups = netdev_trig_groups,
> > };
> > +EXPORT_SYMBOL_GPL(netdev_led_trigger);
>
> If these are going to be exported, maybe they should be made const to
> protect them a bit?
The trigger structure must be defined writable, for the code holds
a list of LEDs that have this trigger activated in the structure, among
other data. I don't think if it can be declared as const and then
defined non-const.
Marek
