Here is a quick-hack patch for /sys/dev/ic/am7990.c that will fix the
'le0: carrier lost" problem with the Sun 4m systems.  After you apply
the patch and rebuild your kernel, you need to add the 'link0' option
to /etc/hostname.le0 or wherver is appropriate for your system to enable
the twisted pair port.  Without the 'link0' option, the AUI port is enabled.

79a80,83
> #ifdef SUN4M
> #define  D_TPE		0x00400000	/* Twisted Pair Ethernet */
> #endif
> 
292a297,305
> #ifdef SUN4M
> 	if (sc->sc_dma->sc_regs) {
> 		if (ifp->if_flags & IFF_LINK0) 
> 			sc->sc_dma->sc_regs->csr |= D_TPE;
> 	 	else 
> 			sc->sc_dma->sc_regs->csr &= ~D_TPE;
> 	}
> #endif

-- 
--------------------------------------------------------------------------
Matt Ragan  (matt@ibmoto.com)  Motorola/IBM Somerset PowerPC Design Center
Network Administrator          Systems/Network Engineering  (512) 795-7298
9737 Great Hills Trail         Austin, Tx  78759        FAX (512) 795-7519
--------------------------------------------------------------------------