ieee802154: energy detection question

ieee802154: energy detection question

[Miquel Raynal]

Hello,

I know this may sound like a silly question but while looking at the
various drivers implementations I found no users (at all) of the ->ed()
energy detection hook. Its comment says that the mac layer is supposed
to use it but I couldn't find where. Of course, the fact that the
abbreviation ends like half of the word in english "-ed" does not help
grepping for that, but I could not figure out how useful this callback
was. In particular since it is mandatory to provide.

I am pretty sure I missed something, so perhaps someone has a pointer
to help me there.

Thanks a lot!
Miquèl

Re: ieee802154: energy detection question

[Alexander Aring]

Hi,

On Fri, Feb 17, 2023 at 4:01 AM Miquel Raynal <miquel.raynal@bootlin.com> wrote:
>
> Hello,
>
> I know this may sound like a silly question but while looking at the
> various drivers implementations I found no users (at all) of the ->ed()
> energy detection hook. Its comment says that the mac layer is supposed
> to use it but I couldn't find where. Of course, the fact that the
> abbreviation ends like half of the word in english "-ed" does not help
> grepping for that, but I could not figure out how useful this callback
> was. In particular since it is mandatory to provide.
>

There is no user, there was never an upstream user.

> I am pretty sure I missed something, so perhaps someone has a pointer
> to help me there.

I think there were some non-upstream users for code which never came
upstream. Please don't look into this code.

What do you want to do with this functionality? But the finger out and
look for a suitable channel to switch and operate on?

- Alex

Re: ieee802154: energy detection question

[Miquel Raynal]

Hi Alexander,

aahringo@redhat.com wrote on Mon, 20 Feb 2023 21:58:04 -0500:

> Hi,
> 
> On Fri, Feb 17, 2023 at 4:01 AM Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> >
> > Hello,
> >
> > I know this may sound like a silly question but while looking at the
> > various drivers implementations I found no users (at all) of the ->ed()
> > energy detection hook. Its comment says that the mac layer is supposed
> > to use it but I couldn't find where. Of course, the fact that the
> > abbreviation ends like half of the word in english "-ed" does not help
> > grepping for that, but I could not figure out how useful this callback
> > was. In particular since it is mandatory to provide.
> >  
> 
> There is no user, there was never an upstream user.

Ah, thanks a lot for the confirmation.

> > I am pretty sure I missed something, so perhaps someone has a pointer
> > to help me there.  
> 
> I think there were some non-upstream users for code which never came
> upstream. Please don't look into this code.
> 
> What do you want to do with this functionality? But the finger out and
> look for a suitable channel to switch and operate on?

Yeah, the idea of having a mac hook for that feels odd, but why not.
What is bothering me actually is the fact that this hook seems mandatory
(while mostly useless), see:
https://elixir.bootlin.com/linux/latest/source/net/mac802154/main.c#L53

I propose to remove that check regarding the ->ed() callback presence?

Thanks,
Miquèl