From da84b3961fcc4dfee091e81071aee78a8233287c Mon Sep 17 00:00:00 2001
From: Pyun YongHyeon <yongari@FreeBSD.org>
Date: Thu, 20 Jul 2006 04:18:45 +0000
Subject: [PATCH] Since resetting hardware takes a very long time and results
 in link renegotiation, we only initialize the hardware only when it is
 absolutely required. Process SIOCGIFADDR ioctl in em(4) when we know an IPv4
 address is added. Handling SIOCGIFADDR in a driver is layering violation but
 it seems that there is no easy way without rewritting hardware initialization
 code to reduce settle time after reset.

This should fix a long standing bug which didn't send ARP packet when
interface address is changed or an alias address is added. Another
effect of this fix is it doesn't need additional delays anymore when
adding an alias address to the interface.
While I'm here add a new if_flags into softc which remembers current
prgroammed interface flags and make use of it when we have to program
promiscuous mode.

Tested by:	Atanas <atanas AT asd DOT aplus DOT net>
Analyzed by:	rwatson
Discussed with:	-stable
---
 sys/dev/em/if_em.c | 38 +++++++++++++++++++++++++++++---------
 sys/dev/em/if_em.h |  1 +
 2 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/sys/dev/em/if_em.c b/sys/dev/em/if_em.c
index e6bc244d201..f90062a48eb 100644
--- a/sys/dev/em/if_em.c
+++ b/sys/dev/em/if_em.c
@@ -67,6 +67,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include <netinet/in_systm.h>
 #include <netinet/in.h>
+#include <netinet/if_ether.h>
 #include <netinet/ip.h>
 #include <netinet/tcp.h>
 #include <netinet/udp.h>
@@ -748,6 +749,7 @@ em_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
 {
 	struct em_softc	*sc = ifp->if_softc;
 	struct ifreq *ifr = (struct ifreq *)data;
+	struct ifaddr *ifa = (struct ifaddr *)data;
 	int error = 0;
 
 	if (sc->in_detach)
@@ -756,8 +758,23 @@ em_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
 	switch (command) {
 	case SIOCSIFADDR:
 	case SIOCGIFADDR:
-		IOCTL_DEBUGOUT("ioctl rcv'd: SIOCxIFADDR (Get/Set Interface Addr)");
-		ether_ioctl(ifp, command, data);
+		if (ifa->ifa_addr->sa_family == AF_INET) {
+			/*
+			 * XXX
+			 * Since resetting hardware takes a very long time
+			 * and results in link renegotiation we only
+			 * initialize the hardware only when it is absolutely
+			 * required.
+			 */
+			ifp->if_flags |= IFF_UP;
+			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
+				EM_LOCK(sc);
+				em_init_locked(sc);
+				EM_UNLOCK(sc);
+			}
+			arp_ifinit(ifp, ifa);
+		} else
+			error = ether_ioctl(ifp, command, data);
 		break;
 	case SIOCSIFMTU:
 	    {
@@ -806,17 +823,20 @@ em_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
 		IOCTL_DEBUGOUT("ioctl rcv'd: SIOCSIFFLAGS (Set Interface Flags)");
 		EM_LOCK(sc);
 		if (ifp->if_flags & IFF_UP) {
-			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
+			if ((ifp->if_drv_flags & IFF_DRV_RUNNING)) {
+				if ((ifp->if_flags ^ sc->if_flags) &
+				    IFF_PROMISC) {
+					em_disable_promisc(sc);
+					em_set_promisc(sc);
+				}
+			} else
 				em_init_locked(sc);
-			}
-
-			em_disable_promisc(sc);
-			em_set_promisc(sc);
 		} else {
 			if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
 				em_stop(sc);
 			}
 		}
+		sc->if_flags = ifp->if_flags;
 		EM_UNLOCK(sc);
 		break;
 	case SIOCADDMULTI:
@@ -882,8 +902,8 @@ em_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
 		break;
 	    }
 	default:
-		IOCTL_DEBUGOUT1("ioctl received: UNKNOWN (0x%x)", (int)command);
-		error = EINVAL;
+		error = ether_ioctl(ifp, command, data);
+		break;
 	}
 
 	return (error);
diff --git a/sys/dev/em/if_em.h b/sys/dev/em/if_em.h
index d36de52b6f2..e7f96f793ca 100644
--- a/sys/dev/em/if_em.h
+++ b/sys/dev/em/if_em.h
@@ -259,6 +259,7 @@ struct em_softc {
 	struct callout	timer;
 	struct callout	tx_fifo_timer;
 	int		io_rid;
+	int		if_flags;
 	struct mtx	mtx;
 	int		em_insert_vlan_header;
 	struct task	link_task;