wierd lockups on KNE100TX (DEC DC21142 (rev 65))

Donald Becker becker@cesdis1.gsfc.nasa.gov
Sat Oct 2 00:44:44 1999

On Fri, 1 Oct 1999, Ruediger Oberhage wrote:

> > > We have a 3com SuperStack II Switch 3900-36 that seems to reboot
> > > spontaneously.  Whenever it does, it takes down networking on all
> > > the machines on it that have DEC DC21142 (rev 65).
> Us, we too have DEC 21142/3 (rev 65)s in Adaptec's 6911A/TX boards.
> > > when this happens, these machines are no longer able to transfer
> > > any data. The card is basically locked up.  I have tried [...]
> What I find remarkable here is the following: there seems to be a
> more generic problem with link-loss with this chip and obviously
> different (and independant) kinds of drivers. The tip to activate
> re-negotiation, e.g. by pulling the plug, badly fails, at least
> here for the OPENSTEP driver and our Linux tulip version driver.
> Thus such a try might actually provoke the "hanging" problem.

Please provoke this behavior and then run 'mii-diag -R' to see if the link
because usable.

If it does, please provoke the behavior and then send some packets to see if
you get a transmit timeout message.  If you do, I can put a MII transceiver
reset in the transmit timeout routine, perhaps conditional on the
transceiver type.

    if (media_cap[dev->if_port] & MediaIsMII) {
-    	/* Do nothing -- the media monitor should handle this. */
+    	/* Reset to recover from a possible transceiver hang. */
+   	mdio_write(dev, tp->phys[0], 0, 0x8000);
	if (tulip_debug > 1)
		printk(KERN_WARNING "%s: Transmit timeout using MII device.\n",

Donald Becker					  becker@cesdis.gsfc.nasa.gov
USRA-CESDIS, Center of Excellence in Space Data and Information Sciences.
Code 930.5, Goddard Space Flight Center,  Greenbelt, MD.  20771
301-286-0882	     http://cesdis.gsfc.nasa.gov/people/becker/whoiam.html