Re: [PATCH net-next 2/2] net: ethernet: mediatek: support custom GMAC label

From: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
To: Andrew Lunn <andrew@lunn.ch>
Cc: "David S. Miller" <davem@davemloft.net>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Felix Fietkau" <nbd@nbd.name>, "John Crispin" <john@phrozen.org>,
	"Sean Wang" <sean.wang@mediatek.com>,
	"Mark Lee" <Mark-MC.Lee@mediatek.com>,
	"Matthias Brugger" <matthias.bgg@gmail.com>,
	"Russell King" <linux@armlinux.org.uk>,
	netdev@vger.kernel.org,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
	<devicetree@vger.kernel.org>,
	"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org,
	"René van Dorst" <opensource@vdorst.com>
Subject: Re: [PATCH net-next 2/2] net: ethernet: mediatek: support custom GMAC label
Date: Mon, 19 Apr 2021 08:04:10 -0700	[thread overview]
Message-ID: <CALCv0x2SSGjiqKOBhK1GT2ksjc9J--Qm3Uq-0xc3sgHvDju5-A@mail.gmail.com> (raw)
In-Reply-To: <YH10UNuJZ5s7dfLh@lunn.ch>

On Mon, Apr 19, 2021 at 5:15 AM Andrew Lunn <andrew@lunn.ch> wrote:
>
> On Sun, Apr 18, 2021 at 09:03:52PM -0700, Ilya Lipnitskiy wrote:
> > The MAC device name can now be set within DTS file instead of always
> > being "ethX". This is helpful for DSA to clearly label the DSA master
> > device and distinguish it from DSA slave ports.
> >
> > For example, some devices, such as the Ubiquiti EdgeRouter X, may have
> > ports labeled ethX. Labeling the master GMAC with a different prefix
> > than DSA ports helps with clarity.
> >
> > Suggested-by: René van Dorst <opensource@vdorst.com>
> > Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
> > ---
> >  drivers/net/ethernet/mediatek/mtk_eth_soc.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> > index 6b00c12c6c43..4c0ce4fb7735 100644
> > --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> > +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> > @@ -2845,6 +2845,7 @@ static const struct net_device_ops mtk_netdev_ops = {
> >
> >  static int mtk_add_mac(struct mtk_eth *eth, struct device_node *np)
> >  {
> > +     const char *label = of_get_property(np, "label", NULL);
> >       const __be32 *_id = of_get_property(np, "reg", NULL);
> >       phy_interface_t phy_mode;
> >       struct phylink *phylink;
> > @@ -2940,6 +2941,9 @@ static int mtk_add_mac(struct mtk_eth *eth, struct device_node *np)
> >       else
> >               eth->netdev[id]->max_mtu = MTK_MAX_RX_LENGTH_2K - MTK_RX_ETH_HLEN;
> >
> > +     if (label)
> > +             strscpy(eth->netdev[id]->name, label, IFNAMSIZ);
>
> It is better to use alloc_netdev_mqs() so you get validation the name
> is unique.
It doesn't look like the name validation happens until the netdev is
registered, and it does not get registered at alloc, right?

I do agree that it's better to use the correct name in the first place
instead of renaming, regardless, so using alloc_netdev_mqs() seems
like a better solution - I'll make the change.

Ilya