Re: let vlan(4) mtu be limited by the parents hardmtu instead of current mtu

[David Gwynne]

On Tue, Aug 26, 2014 at 09:11:14PM -0400, Brad Smith wrote:
> On 20/08/14 8:03 PM, David Gwynne wrote:
> >sthen@ says this is likely a bit optimistic. while most of our drivers 
> >unconditionally configure their max mru, there's some stupid ones that still 
> >interpret the configured mtu as a what the mru should be.
> >
> >dlg
> 
> oce(4) and ix(4) need to be fixed.

this might fix ix(4). anyone able to test?

Index: if_ix.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/if_ix.c,v
retrieving revision 1.99
diff -u -p -r1.99 if_ix.c
--- if_ix.c     26 Aug 2014 11:01:22 -0000      1.99
+++ if_ix.c     27 Aug 2014 11:16:53 -0000
@@ -441,18 +441,6 @@ ixgbe_ioctl(struct ifnet * ifp, u_long c
 #endif
                break;
 
-       case SIOCSIFMTU:
-               IOCTL_DEBUGOUT("ioctl: SIOCSIFMTU (Set Interface MTU)");
-               if (ifr->ifr_mtu < ETHERMIN || ifr->ifr_mtu > ifp->if_hardmtu)
-                       error = EINVAL;
-               else if (ifp->if_mtu != ifr->ifr_mtu) {
-                       ifp->if_mtu = ifr->ifr_mtu;
-                       sc->max_frame_size =
-                               ifp->if_mtu + ETHER_HDR_LEN + ETHER_CRC_LEN;
-                       ixgbe_init(sc);
-               }
-               break;
-
        case SIOCSIFFLAGS:
                IOCTL_DEBUGOUT("ioctl: SIOCSIFFLAGS (Set Interface Flags)");
                if (ifp->if_flags & IFF_UP) {
@@ -690,7 +678,7 @@ ixgbe_init(void *arg)
        IXGBE_WRITE_REG(&sc->hw, IXGBE_GPIE, gpie);
 
        /* Set MTU size */
-       if (ifp->if_mtu > ETHERMTU) {
+       if (ifp->if_hardmtu > ETHERMTU) {
                mhadd = IXGBE_READ_REG(&sc->hw, IXGBE_MHADD);
                mhadd &= ~IXGBE_MHADD_MFS_MASK;
                mhadd |= sc->max_frame_size << IXGBE_MHADD_MFS_SHIFT;
@@ -1596,7 +1584,7 @@ ixgbe_setup_interface(struct ix_softc *s
        ether_ifattach(ifp);
 
        sc->max_frame_size =
-           ifp->if_mtu + ETHER_HDR_LEN + ETHER_CRC_LEN;
+           ifp->if_hardmtu + ETHER_HDR_LEN + ETHER_CRC_LEN;
 }
 
 void
@@ -2680,7 +2668,7 @@ ixgbe_initialize_receive_units(struct ix
 
        /* Set for Jumbo Frames? */
        hlreg = IXGBE_READ_REG(&sc->hw, IXGBE_HLREG0);
-       if (ifp->if_mtu > ETHERMTU)
+       if (ifp->if_hardmtu > ETHERMTU)
                hlreg |= IXGBE_HLREG0_JUMBOEN;
        else
                hlreg &= ~IXGBE_HLREG0_JUMBOEN;