Re: [net-next 17/18] net: mac802154: Let drivers provide their own beacons implementation

Hi,

On Thu, 6 Jan 2022 at 14:15, Miquel Raynal [off-list ref] wrote:

Hi Alexander,

alex.aring@gmail.com wrote on Wed, 5 Jan 2022 19:23:04 -0500:

...

quoted

A HardMAC driver does not use this driver interface... but there
exists a SoftMAC driver for a HardMAC transceiver. This driver
currently works because we use dataframes only... It will not support
scanning currently and somehow we should make iit not available for
drivers like that and for drivers which don't set symbol duration.
They need to be fixed.

My bad. I did not look at it correctly. I made a mistake when talking
about a hardMAC.

Instead, it is a "custom" low level MAC layer. I believe we can compare
the current mac802154 layer mostly to the MLME that is mentioned in the
spec. Well here the additional layer that needs these hooks would be
the MCPS. I don't know if this will be upstreamed or not, but the need
for these hooks is real if such an intermediate low level MAC layer
gets introduced.

In v2 I will get rid of the two patches adding "driver access" to scans
and beacons in order to facilitate the merge of the big part. Then we
will have plenty of time to discuss how we can create such an interface.
Perhaps I'll be able to propose more code as well to make use of these
hooks, we will see.

That the we have a standardised interface between Ieee802154 and
(HardMAC or SoftMAC(mac802154)) (see cfg802154_ops) which is defined
according the spec would make it more "stable" that it will work with
different HardMAC transceivers (which follows that interface) and
mac802154 stack (which also follows that interface). If I understood
you correctly.
I think this is one reason why we are not having any HardMAC
transceivers driver supported in a proper way yet.

I can also imagine about a hwsim HardMAC transceiver which redirects
cfg802154 to mac802154 SoftMAC instance again (something like that),
to have a virtual HardMAC transceiver for testing purpose, etc. In
theory that should work...

- Alex