RE: [RFC 1/3] ARM: dts: imx28: Add description for L2 switch on XEA board

[Joakim Zhang]

Hi Lukasz,

> -----Original Message-----
> From: Lukasz Majewski <lukma@xxxxxxx>
> Sent: 2021年6月24日 19:21
> To: Joakim Zhang <qiangqing.zhang@xxxxxxx>; Florian Fainelli
> <f.fainelli@xxxxxxxxx>; Andrew Lunn <andrew@xxxxxxx>
> Cc: David S . Miller <davem@xxxxxxxxxxxxx>; Jakub Kicinski
> <kuba@xxxxxxxxxx>; Madalin Bucur (OSS) <madalin.bucur@xxxxxxxxxxx>;
> Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>; Vladimir Oltean
> <olteanv@xxxxxxxxx>; netdev@xxxxxxxxxxxxxxx; Arnd Bergmann
> <arnd@xxxxxxxx>; Mark Einon <mark.einon@xxxxxxxxx>; dl-linux-imx
> <linux-imx@xxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [RFC 1/3] ARM: dts: imx28: Add description for L2 switch on XEA
> board
> 
> Hi Joakim,
> 
> > Hi Lukasz, Florian, Andrew,
> >
> > > > Maybe somebody from NXP can provide input to this discussion - for
> > > > example to sched some light on FEC driver (near) future.
> > >
> > > Seems like some folks at NXP are focusing on the STMMAC controller
> > > these days (dwmac from Synopsys), so maybe they have given up on
> > > having their own Ethernet MAC for lower end products.
> >
> > I am very happy to take participate into this topic, but now I have no
> > experience to DSA and i.MX28 MAC, so I may need some time to increase
> > these knowledge, limited insight could be put to now.
> 
> Ok. No problem :-)
> 
> >
> > Florian, Andrew could comment more and I also can learn from it :-),
> > they are all very experienced expert.
> 
> The main purpose of several RFCs for the L2 switch drivers (for DSA [1] and
> switchdev [2]) was to gain feedback from community as soon as possible
> (despite that the driver lacks some features - like VLAN, FDB, etc).
> 
> >
> > We also want to maintain FEC driver since many SoCs implemented this
> > IP, and as I know we would also use it for future SoCs.
> >
> 
> Florian, Andrew, please correct me if I'm wrong, but my impression is that
> upstreaming the support for L2 switch on iMX depends on FEC driver being
> rewritten to support switchdev?
> 
> If yes, then unfortunately, I don't have time and resources to perform that task
> - that is why I have asked if NXP has any plans to update the FEC (fec_main.c)
> driver.
> 
> 
> Joakim, do you have any plans to re-factor the legacy FEC driver
> (fec_main.c) and introduce new one, which would support the switchdev?
> 
> If NXP is not planning to update the driver, then maybe it would be worth to
> consider adding driver from [2] to mainline? Then I could finish it and provide all
> required features.

I don't have such plan now, and have no confidence to re-factor the legacy FEC driver and introduce new one,
which to support switchdev in a short time. I am not very experienced for FEC driver, since I have just maintained
it for half a year. To be honest, I have no idea in my head right now, we even don't have i.MX28 boards.
I'm so sorry about this, but I am also interested in it, I am finding time to increase related knowledge.

Best Regards,
Joakim Zhang
> 
> Links:
> [1] -
> https://source.denx.de/linux/linux-imx28-l2switch/-/commits/imx28-v5.12-L2-u
> pstream-DSA-RFC_v1
> [2] -
> https://source.denx.de/linux/linux-imx28-l2switch/-/commits/imx28-v5.12-L2-u
> pstream-switchdev-RFC_v1
> 
> > Best Regards,
> > Joakim Zhang
> 
> 
> 
> 
> Best regards,
> 
> Lukasz Majewski
> 
> --
> 
> DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
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