[src/trunk]: src/sys/dev/ic - disable ipv4 checksum offloading as it seems to...

[yamt <yamt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/082b638a58fe
branches:  trunk
changeset: 556031:082b638a58fe
user:      yamt <yamt%NetBSD.org@localhost>
date:      Sat Dec 06 11:27:28 2003 +0000

description:
- disable ipv4 checksum offloading as it seems to have a problem.
- add comments to describe it.

diffstat:

 sys/dev/ic/i82557.c |  20 +++++++++++++-------
 1 files changed, 13 insertions(+), 7 deletions(-)

diffs (44 lines):

diff -r a6d2ad56ca2c -r 082b638a58fe sys/dev/ic/i82557.c
--- a/sys/dev/ic/i82557.c       Sat Dec 06 11:20:55 2003 +0000
+++ b/sys/dev/ic/i82557.c       Sat Dec 06 11:27:28 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: i82557.c,v 1.77 2003/11/02 11:07:45 wiz Exp $  */
+/*     $NetBSD: i82557.c,v 1.78 2003/12/06 11:27:28 yamt Exp $ */
 
 /*-
  * Copyright (c) 1997, 1998, 1999, 2001, 2002 The NetBSD Foundation, Inc.
@@ -73,7 +73,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: i82557.c,v 1.77 2003/11/02 11:07:45 wiz Exp $");
+__KERNEL_RCSID(0, "$NetBSD: i82557.c,v 1.78 2003/12/06 11:27:28 yamt Exp $");
 
 #include "bpfilter.h"
 #include "rnd.h"
@@ -390,14 +390,20 @@
        ifp->if_stop = fxp_stop;
        IFQ_SET_READY(&ifp->if_snd);
 
-       /*
-        * XXX we should have separate IFCAP flags for transmit and receive.
-        * XXX it isn't problem for this paticular driver, though.
-        */
        if (sc->sc_flags & FXPF_IPCB) {
                KASSERT(sc->sc_flags & FXPF_EXT_RFA); /* we have both or none */
+               /*
+                * IFCAP_CSUM_IPv4 seems to have a problem,
+                * at least, on i82550 rev.12.
+                * specifically, it doesn't calculate ipv4 checksum correctly
+                * when sending 20 byte ipv4 header + 1 or 2 byte data.
+                * FreeBSD driver has related comments.
+                *
+                * XXX we should have separate IFCAP flags
+                * for transmit and receive.
+                */
                ifp->if_capabilities =
-                   IFCAP_CSUM_IPv4 | IFCAP_CSUM_TCPv4 | IFCAP_CSUM_UDPv4;
+                   /*IFCAP_CSUM_IPv4 |*/ IFCAP_CSUM_TCPv4 | IFCAP_CSUM_UDPv4;
        }
 
        /*