[realtek] SMC1211TX Media Type Selection

Donald Becker becker@scyld.com
Mon Dec 24 02:27:00 2001

On Tue, 24 Dec 2002, Dohan wrote:

> Hi, I have an SMC1211TX EZCard 10/100 connected to a hub with some windows
> machines. I am having problems with switching the media type with mii-diag.
> I had it working when I first installed it and then I tried switching it to
> 100mbit to find out that my hub is only 10mbit. Then I tried switching it
> back and now it takes a few minutes to transfer a few meg. I want to change
> it to whatever mode hex value of 0xf110 was (I think, if not what should I
> change it to???).

Keep in mind that when 'mii-diag' configures the transceiver, it is not
persistent.  Just power cycle the machine to clear your setting.

> I have changed it to both 10baseT (0xf100) and 10baseT-FDX
> (0xf101). Also, is there a table of these values somehwere. I can't find it
> on the site.

Read the mii-diag page
To understand the details, read

> rtl8139-diag.c:v2.04 8/08/2001 Donald Becker (becker@scyld.com)
>  http://www.scyld.com/diag/index.html
> Index #1: Found a SMC1211TX EZCard 10/100 (RealTek RTL8139) adapter at
> 0x1400.
>  The RTL8139 does not use a MII transceiver.
>  It does have internal MII-compatible registers:
>    Basic mode control register   0x782d.
>    Basic mode status register    0x1100.

Note that these two values are swapped.  The version from 8/22/2001
fixes this minor buglet, but the change wasn't important enough to do a
new release.

>    Autonegotiation Advertisement 0x05e1.
>    Link Partner Ability register 0x0000.

Your link partner isn't N-Way.

It's not clear why you are having a performance problem.

Donald Becker				becker@scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Second Generation Beowulf Clusters
Annapolis MD 21403			410-990-9993