Re: 3c905C: No MII transceiver present / 10 Mbit, half duplex, no link

On Wed, 8 Oct 2003, Bogdan Velcea wrote:

>  I have 2 ethernet cards 3Com905C (Tornado), that gives me some headaches:
> 1. sometimes the cards negotiate to Half-Duplex instead of Full-Duplex ( even if
> a changed the cables, or the switch ), in random situations ( and sometimes on
> huge amount of traffic ):
> 
> 2. the utility from linux, named "mii-tool"  gives me wrong informations about
> the status of my ethernet cards ( I asure you that my Cisco Switch tells me that
> both NICs are on auto-100 auto-FD !):
> 
> # mii-tool
> eth0: 10 Mbit, half duplex, no link
> eth1: 10 Mbit, half duplex, no link

What driver version are you using?
 
> 3. the utility "mii-diag" ( that I found on Scyld FTP site:
> ftp://ftp.scyld.com/pub/diag/mii-diag.c with
> ftp://ftp.scyld.com/pub/diag/libmii.c ) seems to not know the MII settings of my
> NICs:
> 
> # mii-diag eth0
> Basic registers of MII PHY #0:  0000 0000 0000 0000 0000 0000 0000 0000.
>   No MII transceiver present!.

The 'mii-diag' program is telling you that the driver isn't reporting a
transceiver.

> # ./mii-diag --force eth0
> Basic registers of MII PHY #0:  0000 0000 0000 0000 0000 0000 0000 0000.
>   No MII transceiver present!.
>  Basic mode control register 0x0000: Auto-negotiation disabled, with
>  Speed fixed at 10 mbps, half-duplex.

Notice that this is the same as the 'mii-too' report, except that
'mii-diag' told you the status was bogus.


> 4. the "vortex-diag" utility ( from the sime site ) gives me some good
> information, but not that I'm interested ( like Link-State ), and strange
> informations like "MAC settings: half-duplex":
...
>  MII PHY found at address 24, status 782d.
>  MII PHY 0 at #24 transceiver registers:
>    1000 782d 0040 6176 0101 41e1 0003 0000

Errrkkk.  

>  Transceiver selection: 100baseTX.
>    Options: negotiated duplex, link beat required.

Hmmm, did you change the configuration EEPROM from the default?
What was the driver detection message?

> Index #1: Found a 3c905C Tornado 100baseTx adapter at 0xe800.
..
>  Transceiver selection: 100baseTX.
>    Options: force full duplex, link beat required.

Again, this is not the default configuration EEPROM setting!

>  MII PHY found at address 24, status 782d.
>  MII PHY 0 at #24 transceiver registers:
>    1000 782d 0040 6176 05e1 41e1 0003 0000

Yet the driver negotiated anyway...

> 6. I forgot to say that I tryed even to force the settings with this utilities
> and/or with "modprobe 3c59x full_duplex=1 options=4" !

Don't do that!  Forcing full duplex or forcing the transceiver setting
is almost always incorrect.

-- 
Donald Becker				[email protected]
Scyld Computing Corporation		http://www.scyld.com
914 Bay Ridge Road, Suite 220		Scyld Beowulf cluster system
Annapolis MD 21403			410-990-9993

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