octeon/cnmac: assume 1Gbps in the default case

avoids a division by 0 when up'ing the non-working cnmac2 on er-poe

feedback from visa@:
"The cnmac2 link is connected to a discrete Ethernet switch chip on the
PoE, and this link does not carry RGMII in-band PHY status.  If the code
were to support such hardware designs in the future, something like this
patch would be needed."

this diff from miod@, same diff from visa@ in 2017
(cf https://marc.info/?l=openbsd-bugs&m=151017517115440&w=2)
ok visa@

diff --git a/sys/arch/octeon/dev/cn30xxgmx.c b/sys/arch/octeon/dev/cn30xxgmx.c
index 5775a1b..fc90edc 100644 (file)
--- a/sys/arch/octeon/dev/cn30xxgmx.c
+++ b/sys/arch/octeon/dev/cn30xxgmx.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: cn30xxgmx.c,v 1.54 2024/05/20 23:13:33 jsg Exp $      */
+/*     $OpenBSD: cn30xxgmx.c,v 1.55 2024/07/08 08:07:45 landry Exp $   */
 
 /*
  * Copyright (c) 2007 Internet Initiative Japan, Inc.
@@ -991,7 +991,8 @@ cn30xxgmx_rgmii_speed(struct cn30xxgmx_port_softc *sc)
                baudrate = IF_Gbps(1);
                break;
        default:
-               baudrate = 0/* XXX */;
+               /* Assume 1Gbps for now */
+               baudrate = IF_Gbps(1); /* XXX */
                break;
        }
        ifp->if_baudrate = baudrate;
@@ -1202,7 +1203,7 @@ cn30xxgmx_rgmii_speed_speed(struct cn30xxgmx_port_softc *sc)
                SET(prt_cfg, PRTN_CFG_SPEED);
                break;
        default:
-               /* NOT REACHED! */
+               /* THEORETICALLY NOT REACHED! */
                /* Following configuration is default value of system.
                */
                tx_clk = 1;