Re: [PATCH can-next v6] can: add tx/rx LED trigger support

From: Fabio Baltieri
Date: Thu Sep 06 2012 - 07:18:08 EST


Hi Kurt,

On Thu, Sep 6, 2012 at 12:33 PM, Kurt Van Dijck <kurt.van.dijck@xxxxxx> wrote:
> On Tue, Sep 04, 2012 at 10:15:53PM +0200, Fabio Baltieri wrote:
>> On Tue, Sep 04, 2012 at 09:11:28AM +0200, Kurt Van Dijck wrote:
> [...]
>> > > The name of the device can only be changed when the interface is down.
>> > > Is it possible to put some scripting around it to detach and attach the leds
>> > > to the interfaces on ifup/ifdown triggers?
>> >
>> > Are the led triggers available for using while the netdev is down then?
>>
>> Sure! On embedded systems triggers are usually attached to actual LEDs
>> at probe time using default_trigger field of struct led_classdev, and
>> that can be specified both in machine files or in device tree.
>
> I also think that led triggers should be available.

Right, that's why I think the only way is to use device name.

> I asked the question because detach & attach leds to interfaces would
> indeed break that.

Sure? I think that the trigger would be set again on reattach, as
default_trigger is checked both in led_cdev probe and
trigger_register, see:

http://lxr.free-electrons.com/source/drivers/leds/led-triggers.c#L180

I'll try that tonight.

> btw, I tried to send a patch tuesday (my first $ git send-email) using
> netdev notifiers: did you receive it, and what do you think of it?

Sure, I got it! I was planning to try that this weekend but I can
give you some comments earlier tonight... sorry for the dealy!

Fabio

--
Fabio Baltieri
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