3c905B doing 10/HD w/ crossover cable

Zwane Mwaikambo (zwane@linux.realnet.co.sz)
Mon, 14 Jan 2002 14:03:09 +0200 (SAST)


Hi Andrew, Jeff
My 3c905B[1] (2.4.18-pre3) always autonegotiates 10baseTx Half
Duplex whenever i use a crossover cable (works fine on a 100 switch and a
10/100 Hub). The link partner is a Realtek RTL-8139A [2] (2.5.2-pre11) and
reports the following if i boot it after the 3com box;

eth0: Setting half-duplex based on auto-negotiated partner ability 0000.

Forcing 100BaseTx/FD on the 3com ends up in nothing being able to go out
the wire (destination host unreachable).

mii-diag on the 3com box gives the following
Basic registers of MII PHY #0: c000 c000 c000 c000 c000 c000 c000 c000.
The autonegotiated capability is 0000.
No common media type was autonegotiated!
This is extremely unusual and typically indicates a configuration error.
Perhaps the advertised capability set was intentionally limited.
Basic mode control register 0xc000: Auto-negotiation disabled, with
Speed fixed at 10 mbps, half-duplex.
Transceiver in loopback mode!
Transceiver currently being reset!
Basic mode status register 0xc000 ... c000.
Link status: not established.
Your link partner advertised c000:.
End of basic transceiver information.

mii-diag on the 8139A box
Basic registers of MII PHY #32: 0000 0000 0000 0000 0000 0000 0000 0000.
Basic mode control register 0x0000: Auto-negotiation disabled, with
Speed fixed at 10 mbps, half-duplex.
Basic mode status register 0x0000 ... 0000.
Link status: not established.
Link partner information is not exchanged when in fixed speed mode.
End of basic transceiver information.

All drivers are modular with no module parameters. The 3com negotiates
100BaseTx/FD in FreeBSD 4.4 and NetBSD 1.5 using the same link partner.

[1] Ethernet controller: 3Com Corporation 3c905B 100BaseTX [Cyclone] (rev 30)
[2] Ethernet controller: Accton Technology Corporation SMC2-1211TX (rev 10)

Thanks,
Zwane Mwaikambo

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/