svn commit: r249509 - head/sys/dev/e1000

[Jack F Vogel]

Author: jfv
Date: Mon Apr 15 17:01:42 2013
New Revision: 249509
URL: http://svnweb.freebsd.org/changeset/base/249509

Log:
  Corrections to the RX checksum code, make sure its disabled as
  well as enabled when necessary. And simplify the checksum routine
  itself, adding UDP bit to the test. Thanks to Kevin Lo for pointing
  out the problems and code suggestions.

Modified:
  head/sys/dev/e1000/if_em.c

Modified: head/sys/dev/e1000/if_em.c
==============================================================================
--- head/sys/dev/e1000/if_em.c	Mon Apr 15 16:09:24 2013	(r249508)
+++ head/sys/dev/e1000/if_em.c	Mon Apr 15 17:01:42 2013	(r249509)
@@ -4322,11 +4322,12 @@ em_initialize_receive_unit(struct adapte
 		E1000_WRITE_REG(hw, E1000_RFCTL, E1000_RFCTL_ACK_DIS);
 	}
 
-	if (ifp->if_capenable & IFCAP_RXCSUM) {
-		rxcsum = E1000_READ_REG(hw, E1000_RXCSUM);
-		rxcsum |= (E1000_RXCSUM_IPOFL | E1000_RXCSUM_TUOFL);
-		E1000_WRITE_REG(hw, E1000_RXCSUM, rxcsum);
-	}
+	rxcsum = E1000_READ_REG(hw, E1000_RXCSUM);
+	if (ifp->if_capenable & IFCAP_RXCSUM)
+		rxcsum |= E1000_RXCSUM_TUOFL;
+	else
+		rxcsum &= ~E1000_RXCSUM_TUOFL;
+	E1000_WRITE_REG(hw, E1000_RXCSUM, rxcsum);
 
 	/*
 	** XXX TEMPORARY WORKAROUND: on some systems with 82573
@@ -4644,31 +4645,23 @@ em_fixup_rx(struct rx_ring *rxr)
 static void
 em_receive_checksum(struct e1000_rx_desc *rx_desc, struct mbuf *mp)
 {
+	mp->m_pkthdr.csum_flags = 0;
+
 	/* Ignore Checksum bit is set */
-	if (rx_desc->status & E1000_RXD_STAT_IXSM) {
-		mp->m_pkthdr.csum_flags = 0;
+	if (rx_desc->status & E1000_RXD_STAT_IXSM)
 		return;
-	}
-
-	if (rx_desc->status & E1000_RXD_STAT_IPCS) {
-		/* Did it pass? */
-		if (!(rx_desc->errors & E1000_RXD_ERR_IPE)) {
-			/* IP Checksum Good */
-			mp->m_pkthdr.csum_flags = CSUM_IP_CHECKED;
-			mp->m_pkthdr.csum_flags |= CSUM_IP_VALID;
 
-		} else {
-			mp->m_pkthdr.csum_flags = 0;
-		}
-	}
+	if (rx_desc->errors & (E1000_RXD_ERR_TCPE | E1000_RXD_ERR_IPE))
+		return;
 
-	if (rx_desc->status & E1000_RXD_STAT_TCPCS) {
-		/* Did it pass? */
-		if (!(rx_desc->errors & E1000_RXD_ERR_TCPE)) {
-			mp->m_pkthdr.csum_flags |=
-			(CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
-			mp->m_pkthdr.csum_data = htons(0xffff);
-		}
+	/* IP Checksum Good? */
+	if (rx_desc->status & E1000_RXD_STAT_IPCS)
+		mp->m_pkthdr.csum_flags = (CSUM_IP_CHECKED | CSUM_IP_VALID);
+
+	/* TCP or UDP checksum */
+	if (rx_desc->status & (E1000_RXD_STAT_TCPCS | E1000_RXD_STAT_UDPCS)) {
+		mp->m_pkthdr.csum_flags |= (CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
+		mp->m_pkthdr.csum_data = htons(0xffff);
 	}
 }