82xx fcc_enet problem between Linux 2.4 and 2.6

82xx fcc_enet problem between Linux 2.4 and 2.6

[Laurent Lagrange]

Hello,

I work on several custom 82xx boards with Linux 2.4 and 2.6.

I have ported Linux 2.6.9 on different boards and I noticed
that I have tx carrier errors on my FCC ports. Almost one
error per xmit.

I reinstalled Linux 2.4.18 on these boards and I have NO ERROR.

The errors arise with PHY configured in 100M full duplex (or autoneg).
The FCC has the same duplex as PHY.

I found on web another mail concerning a problem on PQ2FADS Linux2.6.8
when mounting a NFS. The writer has also noticed that he has
tx carrier errors but the mail focused on mount and not FCC.

> # ifconfig
> eth0      Link encap:Ethernet  HWaddr 08:00:17:40:00:03
>           inet addr:192.168.0.5  Bcast:192.168.0.255  Mask:255.255.255.0
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:122 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:114 errors:0 dropped:0 overruns:0 carrier:114
>           collisions:0 txqueuelen:1000
>           RX bytes:20747 (20.2 kb)  TX bytes:14320 (13.9 kb)
>           Base address:0x8500

I think this is not a phy or hardware problem but rather a FCC configuration
mismatch in fcc_enet.c.

Thanks for any tips
Laurent

Re: 82xx fcc_enet problem between Linux 2.4 and 2.6

[Bastos Fernandez Alexandre]

Laurent,

>
> I work on several custom 82xx boards with Linux 2.4 and 2.6.
>
> I have ported Linux 2.6.9 on different boards and I noticed
> that I have tx carrier errors on my FCC ports. Almost one
> error per xmit.
>

I have experienced same problem. I suppose you are using the old
fcc driver in /arch/ppc

> I reinstalled Linux 2.4.18 on these boards and I have NO ERROR.
>
> The errors arise with PHY configured in 100M full duplex (or autoneg).
> The FCC has the same duplex as PHY.

Are you sure? In my case, the problem was that while the PHY had autoneg
to full-duplex, the MAC kept in half-duplex mode

> [...]
>
> I think this is not a phy or hardware problem but rather a FCC configuration
> mismatch in fcc_enet.c.
>

Yes. But I thing the driver has been obsoleted by fs_enet one,
so modifiying it now has no sense.

Best regards,

Alex BASTOS

RE: 82xx fcc_enet problem between Linux 2.4 and 2.6

[Laurent Lagrange]

Hello Alex,

> > I have ported Linux 2.6.9 on different boards and I noticed
> > that I have tx carrier errors on my FCC ports. Almost one
> > error per xmit.
> I have experienced same problem. I suppose you are using the old
> fcc driver in /arch/ppc
Yes that's right.

> > I reinstalled Linux 2.4.18 on these boards and I have NO ERROR.
> > The errors arise with PHY configured in 100M full duplex (or autoneg).
> > The FCC has the same duplex as PHY.
> Are you sure? In my case, the problem was that while the PHY had autoneg
> to full-duplex, the MAC kept in half-duplex mode
I have modified some code in fcc_enet.c for Linux 2.4 to manage PHY as I
wanted.
Perhaps was I in luck to correct something wrong. I checked that the duplex
were identical for FCC and PHY and I had no carrier error.

> > I think this is not a phy or hardware problem but rather a
> FCC configuration mismatch in fcc_enet.c.
> Yes. But I think the driver has been obsoleted by fs_enet one,
> so modifiying it now has no sense.
Yes I retreived fs_enet in Linux 2.6.15 and I'll try it.
This driver seems to appear in Linux 2.6.11 tree not before.
Is it right ?

Thanks very much for your reply.
Best regards
Laurent