Thu Apr 23 15:54:36 2020 UTC ()
elaborate on why we don't support hardware checksum offloading, and probably
never will


(jdolecek)
diff -r1.23 -r1.24 src/share/man/man4/sk.4
cvs diff -r1.23 -r1.24 src/share/man/man4/sk.4 (expand / switch to unified diff)

--- src/share/man/man4/sk.4 2019/08/30 09:24:19 1.23
+++ src/share/man/man4/sk.4 2020/04/23 15:54:36 1.24
@@ -1,14 +1,14 @@ @@ -1,14 +1,14 @@
1.\" $NetBSD: sk.4,v 1.23 2019/08/30 09:24:19 wiz Exp $ 1.\" $NetBSD: sk.4,v 1.24 2020/04/23 15:54:36 jdolecek Exp $
2.\" 2.\"
3.\" Copyright (c) 2003, The NetBSD Foundation, Inc. 3.\" Copyright (c) 2003, The NetBSD Foundation, Inc.
4.\" All rights reserved. 4.\" All rights reserved.
5.\" 5.\"
6.\" Redistribution and use in source and binary forms, with or without 6.\" Redistribution and use in source and binary forms, with or without
7.\" modification, are permitted provided that the following conditions 7.\" modification, are permitted provided that the following conditions
8.\" are met: 8.\" are met:
9.\" 1. Redistributions of source code must retain the above copyright 9.\" 1. Redistributions of source code must retain the above copyright
10.\" notice, this list of conditions and the following disclaimer. 10.\" notice, this list of conditions and the following disclaimer.
11.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" 2. Redistributions in binary form must reproduce the above copyright
12.\" notice, this list of conditions and the following disclaimer in the 12.\" notice, this list of conditions and the following disclaimer in the
13.\" documentation and/or other materials provided with the distribution. 13.\" documentation and/or other materials provided with the distribution.
14.\" 14.\"
@@ -48,27 +48,27 @@ @@ -48,27 +48,27 @@
48.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 48.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
49.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 49.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
50.\" ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD 50.\" ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
51.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 51.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
52.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 52.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
53.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 53.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
54.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 54.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
55.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 55.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
56.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 56.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
57.\" THE POSSIBILITY OF SUCH DAMAGE. 57.\" THE POSSIBILITY OF SUCH DAMAGE.
58.\" 58.\"
59.\" $FreeBSD: src/share/man/man4/man4.i386/sk.4,v 1.3 1999/08/28 00:20:29 peter Exp $ 59.\" $FreeBSD: src/share/man/man4/man4.i386/sk.4,v 1.3 1999/08/28 00:20:29 peter Exp $
60.\" 60.\"
61.Dd August 24, 2019 61.Dd April 23, 2020
62.Dt SK 4 62.Dt SK 4
63.Os 63.Os
64.Sh NAME 64.Sh NAME
65.Nm sk , 65.Nm sk ,
66.Nm skc , 66.Nm skc ,
67.Nm msk , 67.Nm msk ,
68.Nm mskc 68.Nm mskc
69.Nd SysKonnect XMAC II and Marvell GMAC based Gigabit Ethernet 69.Nd SysKonnect XMAC II and Marvell GMAC based Gigabit Ethernet
70.Sh SYNOPSIS 70.Sh SYNOPSIS
71.Cd "skc* at pci? dev ? function ?" 71.Cd "skc* at pci? dev ? function ?"
72.Cd "sk* at skc?" 72.Cd "sk* at skc?"
73.Cd "mskc* at pci? dev ? function ?" 73.Cd "mskc* at pci? dev ? function ?"
74.Cd "msk* at mskc?" 74.Cd "msk* at mskc?"
@@ -275,20 +275,26 @@ driver first appeared in @@ -275,20 +275,26 @@ driver first appeared in
275.Ox 4.0 , 275.Ox 4.0 ,
276and was ported to 276and was ported to
277.Nx 4.0 . 277.Nx 4.0 .
278.Sh AUTHORS 278.Sh AUTHORS
279.An -nosplit 279.An -nosplit
280The 280The
281.Nm 281.Nm
282driver was written by 282driver was written by
283.An Bill Paul Aq Mt wpaul@ctr.columbia.edu . 283.An Bill Paul Aq Mt wpaul@ctr.columbia.edu .
284Support for the Marvell Yukon-2 was added by 284Support for the Marvell Yukon-2 was added by
285.An Mark Kettenis Aq Mt kettenis@openbsd.org . 285.An Mark Kettenis Aq Mt kettenis@openbsd.org .
286.Sh BUGS 286.Sh BUGS
287Support for checksum offload is unimplemented. 287Support for checksum offload is unimplemented.
 288Particularly for Yukon-II hardware, there are multiple different
 289receive and transmit offload silicon bugs which have to be worked
 290around in software when using hardware offloading.
 291For this reason, support for hardware offloading
 292is not very desirable for therse controllers, and unlikely to be
 293ever implemented.
288.Pp 294.Pp
289Performance with at least some Marvell-based adapters is poor, 295Performance with at least some Marvell-based adapters is poor,
290especially on loaded PCI buses or when the adapters are behind 296especially on loaded PCI buses or when the adapters are behind
291PCI-PCI bridges. 297PCI-PCI bridges.
292It is believed that this is because the Marvell parts have 298It is believed that this is because the Marvell parts have
293significantly less buffering than the original SysKonnect cards 299significantly less buffering than the original SysKonnect cards
294had. 300had.