Recently spotted on bugzilla for 2.6. A missing E8390_CMD constant has no effect on i386 since it is zero, but some other arch. use Alan's register mapping (mac8390, etc) which may have non-zero E8390_CMD.
Paul.
--- linux-386/drivers/net/8390.c~ Sat Aug 7 19:26:05 2004 +++ linux-386/drivers/net/8390.c Wed Jan 5 22:27:10 2005 @@ -1143,7 +1143,7 @@ static void NS8390_trigger_send(struct n outb_p(E8390_NODMA+E8390_PAGE0, e8390_base+E8390_CMD); - if (inb_p(e8390_base) & E8390_TRANS) + if (inb_p(e8390_base+E8390_CMD) & E8390_TRANS) { printk(KERN_WARNING "%s: trigger_send() called with the transmitter busy.\n", dev->name);