Re: [PATCH wpan-next 01/20] net: mac802154: Allow the creation of coordinator interfaces

From: Alexander Aring <aahringo@redhat.com>
To: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Alexander Aring <alex.aring@gmail.com>,
	Stefan Schmidt <stefan@datenfreihafen.org>,
	linux-wpan - ML <linux-wpan@vger.kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Eric Dumazet <edumazet@google.com>,
	Network Development <netdev@vger.kernel.org>,
	David Girault <david.girault@qorvo.com>,
	Romuald Despres <romuald.despres@qorvo.com>,
	Frederic Blain <frederic.blain@qorvo.com>,
	Nicolas Schodet <nico@ni.fr.eu.org>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Subject: Re: [PATCH wpan-next 01/20] net: mac802154: Allow the creation of coordinator interfaces
Date: Sat, 3 Sep 2022 10:31:37 -0400	[thread overview]
Message-ID: <CAK-6q+gW=s=tWBrkN=CaiyoLM8kqeF0iRuS21AqDMQdQcE9H5A@mail.gmail.com> (raw)
In-Reply-To: <CAK-6q+hO1i=xvXx3wHo658ph93FwuVs_ssjG0=jnphEe8a+gxw@mail.gmail.com>

Hi,

On Sat, Sep 3, 2022 at 10:20 AM Alexander Aring <aahringo@redhat.com> wrote:
>
> Hi,
>
> On Fri, Sep 2, 2022 at 8:08 PM Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> ...
> > >
> > > I am sorry, I never looked into Zephyr for reasons... Do they not have
> > > something like /proc/interrupts look if you see a counter for your
> > > 802.15.4 transceiver?
> > >
> > > > Also, can you please clarify when are we talking about software and
> > > > when about hardware filters.
> > > >
> > >
> > > Hardware filter is currently e.g. promiscuous mode on or off setting.
> > > Software filtering is depending which receive path the frame is going
> > > and which hardware filter is present which then acts like actually
> > > with hardware filtering.
> > > I am not sure if this answers this question?
> >
> > I think my understand gets clearer now that I've digged into Zephyr's
> > ieee802154 layer and in the at86rf230 datasheet.
> >
>
> okay, I think for zephyr questions you are here on the wrong mailinglist.
>
> > I will answer the previous e-mail but just for not I wanted to add that
> > I managed to get Zephyr working, I had to mess around in the code a
> > little bit and actually I discovered a net command which is necessary
> > to use in order to turn the iface up, whatever.
> >
>
> aha.
>
> > So I was playing with the atusb devices and I _think_ I've found a
> > firmware bug or a hardware bug which is going to be problematic. In
>
> the firmware is open source, I think it's fine to send patches here (I
> did it as well once for do a quick hack to port it to rzusb) the atusb
> is "mostly" at the point that they can do open hardware from the
> qi-hardware organization.
>
> > iface.c, when creating the interface, if you set the hardware filters
> > (set_panid/short/ext_addr()) there is no way you will be able to get a
> > fully transparent promiscuous mode. I am not saying that the whole
>
> What is a transparent promiscuous mode?
>
> > promiscuous mode does not work anymore, I don't really know. What I was
> > interested in were the acks, and getting them is a real pain. At least,
> > enabling the promiscuous mode after setting the hw filters will lead to
> > the acks being dropped immediately while if the promiscuous mode is
> > enabled first (like on monitor interfaces) the acks are correctly
> > forwarded by the PHY.
>
> If we would not disable AACK handling (means we receive a frame with
> ack requested bit set we send a ack back) we would ack every frame it
> receives (speaking on at86rf233).
>
> >
> > While looking at the history of the drivers, I realized that the
> > TX_ARET mode was not supported by the firmware in 2015 (that's what you
>
> There exists ARET and AACK, both are mac mechanisms which must be
> offloaded on the hardware. Note that those only do "something" if the
> ack request bit in the frame is set.
>
> ARET will retransmit if no ack is received after some while, etc.
> mostly coupled with CSMA/CA handling. We cannot guarantee such timings
> on the Linux layer. btw: mac80211 can also not handle acks on the
> software layer, it must be offloaded.
>
> AACK will send a back if a frame with ack request bit was received.

will send an ack back*

- Alex