Received-SPF: pass (google.com: domain of linux-kernel+bounces-163936-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
Date: Tue, 30 Apr 2024 14:52:43 +0200
From: Lukasz Majewski <lukma@denx.de>
To: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org, Paolo Abeni <pabeni@redhat.com>, Casper
 Andersson <casper.casan@gmail.com>, Andrew Lunn <andrew@lunn.ch>, Eric
 Dumazet <edumazet@google.com>, Vladimir Oltean <olteanv@gmail.com>, "David
 S. Miller" <davem@davemloft.net>, Oleksij Rempel <o.rempel@pengutronix.de>,
 Tristram.Ha@microchip.com, Sebastian Andrzej Siewior
 <bigeasy@linutronix.de>, Ravi Gunasekaran <r-gunasekaran@ti.com>, Simon
 Horman <horms@kernel.org>, Nikita Zhandarovich <n.zhandarovich@fintech.ru>,
 Murali Karicheri <m-karicheri2@ti.com>, Jiri Pirko <jiri@resnulli.us>, Dan
 Carpenter <dan.carpenter@linaro.org>, Ziyang Xuan
 <william.xuanziyang@huawei.com>, Shigeru Yoshida <syoshida@redhat.com>,
 "Ricardo B. Marliere" <ricardo@marliere.net>, linux-kernel@vger.kernel.org
Subject: Re: [net-next PATCH] hsr: Simplify code for announcing HSR nodes
 timer setup
Message-ID: <20240430145243.34b82105@wsk>
In-Reply-To: <20240429104026.0fe3de0f@kernel.org>
References: <20240425153958.2326772-1-lukma@denx.de>
	<20240426173317.2f6228a0@kernel.org>
	<20240429120904.2ab5248c@wsk>
	<20240429104026.0fe3de0f@kernel.org>
Organization: denx.de
Precedence: bulk
MIME-Version: 1.0
Content-Type: multipart/signed; boundary="Sig_/Bw.S4.DcI2Q_96DL9tIqW/s";
 protocol="application/pgp-signature"; micalg=pgp-sha512

--Sig_/Bw.S4.DcI2Q_96DL9tIqW/s
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: quoted-printable

Hi Jakub,

> On Mon, 29 Apr 2024 12:09:04 +0200 Lukasz Majewski wrote:
> > > if the
> > > timer is already running we'll mess with the spacing of the
> > > frames, no?   =20
> >=20
> > When NETDEV_CHANGE is trigger for reason different than carrier (or
> > port state) change and the netif_oper_up() returns true, the period
> > for HSR supervisory frames (i.e. HSR_ANNOUNCE_INTEVAL) would be
> > violated.
> >=20
> > What are here the potential threads? =20
>=20
> Practically speaking I'm not sure if anyone uses any of the weird
> IFF_* flags, but they are defined in uAPI (enum net_device_flags) and
> I don't see much validation so presumably it's possible to flip them.

Ok, I see.

Then - what would you recommend instead? The approach with manual
checking the previous state has described drawbacks.

I've poked around kernel sources and it looks like the netif_oper_up()
is used in conjunction with netif_running():

netif_running(dev) && netif_oper_up(dev)

so, IMHO the netif_running(dev) shall be added to the condition.


In the uapi/include/linux/if.h there are serveral IF_OPER_* flags
defined. It looks to me that only for the IF_OPER_UP the HSR interface
shall send announcement supervisory frames. With other conditions it
shall be turned off.


Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Erika Unter
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de

--Sig_/Bw.S4.DcI2Q_96DL9tIqW/s
Content-Type: application/pgp-signature
Content-Description: OpenPGP digital signature

-----BEGIN PGP SIGNATURE-----

iQEzBAEBCgAdFiEEgAyFJ+N6uu6+XupJAR8vZIA0zr0FAmYw6ZsACgkQAR8vZIA0
zr1vyQf/b9dD0cGGRR2fJR7RDNo7Ul0teNxdptDZ1BEmoUzA+9rqc7FbAks5fMpd
Yryrt5Lf18eUOgKRDXI8p393k61794K4TH6gSHklkI9InLA0pNhkCNufbE79VHhZ
ErviOn4c46V0J7OTlb3dDlmm0/Isg74a0wVboHKgBSvHnHaNlaClxeG3v70i3bBn
aQIVcmCQ3mYRbSY+/A/uOCryp27Ii53Llonk5FY3lLNFX3kwHCZdN9SbgC0OY1wJ
ggPSqcN1lcTuJkwDhdd03K2N6FSMCA8fRRBkj5ei4e4VWEbq/GyRDddS5HV/urox
6q/anTEaL7Haft6BGSgnn8yoB262bA==
=LiR9
-----END PGP SIGNATURE-----

--Sig_/Bw.S4.DcI2Q_96DL9tIqW/s--