From fcec677d3d53ae09637142c7d81de6b9b98916d8 Mon Sep 17 00:00:00 2001
From: Juli Mallett <jmallett@FreeBSD.org>
Date: Fri, 27 Mar 2009 03:17:25 +0000
Subject: [PATCH] o) Check that no overrun or CRC errors were encountered in
 receiving a    packet.  Linux, OpenBSD and our iwn(4) all do this.  It also
 results in    a huge performance improvement (and the rejection of a fair
 number of    apparently-bad packets on receive) on my hardware. o) Like the
 wpi(4) driver in OpenBSD, and like our iwn(4), also drop runt    packets. o)
 Don't bother doing IFQ_POLL and then IFQ_DRV_DEQUEUE, just do   
 IFQ_DRV_DEQUEUE outright.  This is more similar to how OpenBSD and our   
 iwn(4) work.

Reviewed by:	sam
---
 sys/dev/wpi/if_wpi.c    | 17 +++++++++++++++--
 sys/dev/wpi/if_wpireg.h |  2 --
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/sys/dev/wpi/if_wpi.c b/sys/dev/wpi/if_wpi.c
index 776d089f4506..9f186f86e9de 100644
--- a/sys/dev/wpi/if_wpi.c
+++ b/sys/dev/wpi/if_wpi.c
@@ -1473,6 +1473,20 @@ wpi_rx_intr(struct wpi_softc *sc, struct wpi_rx_desc *desc,
 	    le16toh(head->len), (int8_t)stat->rssi, head->rate, head->chan,
 	    (uintmax_t)le64toh(tail->tstamp)));
 
+	/* discard Rx frames with bad CRC early */
+	if ((le32toh(tail->flags) & WPI_RX_NOERROR) != WPI_RX_NOERROR) {
+		DPRINTFN(WPI_DEBUG_RX, ("%s: rx flags error %x\n", __func__,
+		    le32toh(tail->flags)));
+		ifp->if_ierrors++;
+		return;
+	}
+	if (le16toh(head->len) < sizeof (struct ieee80211_frame)) {
+		DPRINTFN(WPI_DEBUG_RX, ("%s: frame too short: %d\n", __func__,
+		    le16toh(head->len)));
+		ifp->if_ierrors++;
+		return;
+	}
+
 	/* XXX don't need mbuf, just dma buffer */
 	mnew = m_getjcl(M_DONTWAIT, MT_DATA, M_PKTHDR, MJUMPAGESIZE);
 	if (mnew == NULL) {
@@ -2029,7 +2043,7 @@ wpi_start_locked(struct ifnet *ifp)
 		return;
 
 	for (;;) {
-		IFQ_POLL(&ifp->if_snd, m);
+		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
 		if (m == NULL)
 			break;
 		/* no QoS encapsulation for EAPOL frames */
@@ -2040,7 +2054,6 @@ wpi_start_locked(struct ifnet *ifp)
 			ifp->if_drv_flags |= IFF_DRV_OACTIVE;
 			break;
 		}
-		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
 		ni = (struct ieee80211_node *) m->m_pkthdr.rcvif;
 		m = ieee80211_encap(ni, m);
 		if (m == NULL) {
diff --git a/sys/dev/wpi/if_wpireg.h b/sys/dev/wpi/if_wpireg.h
index 60692a204e0b..2ccc21fedd75 100644
--- a/sys/dev/wpi/if_wpireg.h
+++ b/sys/dev/wpi/if_wpireg.h
@@ -235,12 +235,10 @@ struct wpi_rx_head {
 
 struct wpi_rx_tail {
 	uint32_t	flags;
-#if 0
 #define WPI_RX_NO_CRC_ERR	(1 << 0)
 #define WPI_RX_NO_OVFL_ERR	(1 << 1)
 /* shortcut for the above */
 #define WPI_RX_NOERROR		(WPI_RX_NO_CRC_ERR | WPI_RX_NO_OVFL_ERR)
-#endif
 	uint64_t	tstamp;
 	uint32_t	tbeacon;
 } __packed;