Re: kern/50933: can not enable the interface capabilities at ixg0

[David Young <dyoung%pobox.com@localhost>]

The following reply was made to PR kern/50933; it has been noted by GNATS.

From: David Young <dyoung%pobox.com@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
	netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/50933: can not enable the interface capabilities at ixg0
Date: Thu, 19 May 2016 15:02:03 -0500

 On Thu, Mar 10, 2016 at 01:35:00PM +0000, 6bone%6bone.informatik.uni-leipzig.de@localhost wrote:
 > >Number:         50933
 > >Category:       kern
 > >Synopsis:       can not enable the interface capabilities at ixg0
 > >Confidential:   no
 > >Severity:       serious
 > >Priority:       medium
 > >Responsible:    kern-bug-people
 > >State:          open
 > >Class:          sw-bug
 > >Submitter-Id:   net
 > >Arrival-Date:   Thu Mar 10 13:35:00 +0000 2016
 > >Originator:     Uwe Toenjes
 > >Release:        netbsd-7
 > >Organization:
 > University of Leipzig
 > >Environment:
 > NetBSD 6bone.informatik.uni-leipzig.de 7.0_STABLE NetBSD 7.0_STABLE (MYCONF7.gdb) #0: Sat Feb 13 12:32:12 CET 2016  root%6bone.informatik.uni-leipzig.de@localhost:/usr/obj/sys/arch/amd64/compile/MYCONF7.gdb amd64
 > 
 > >Description:
 > ifconfig ixg0 reports
 > 
 > ixg0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500
 >         capabilities=fff80<TSO4,IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx>
 >         capabilities=fff80<TCP4CSUM_Tx,UDP4CSUM_Rx,UDP4CSUM_Tx,TCP6CSUM_Rx>
 >         capabilities=fff80<TCP6CSUM_Tx,UDP6CSUM_Rx,UDP6CSUM_Tx,TSO6,LRO>
 >         enabled=42b80<TSO4,IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Tx>
 >         enabled=42b80<UDP4CSUM_Tx,TSO6>
 >         ec_capabilities=7<VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU>
 >         ec_enabled=7<VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU>
 >         address: a0:36:9f:26:8e:7c
 >         media: Ethernet autoselect
 > 
 > I try to activate the capabilities.
 > 
 > I try to activate the capabilities.
 > 
 > ifconfig ixg0 tso4 tso6 - works
 > ifconfig ixg0 ip4csum - works
 > 
 > ifconfig ixg0 tcp4csum
 > ifconfig: SIOCSIFCAP: Invalid argument
 
 On ixg, all of the L4 checksum-offload capabilities (tcp4csum, tcp6csum,
 udp4csum, udp6csum) have to be activated/deactivated together, because
 that is how the hardware works.  If that is not already mentioned in the
 manual page, my apologies.
 
 I would argue that given the limitations of SIOCSIFCAP, today, this is
 the least bad way for ixg offload capabilities to work.  I'd be happy to
 talk on tech-net about how to bring the ioctl interface up to snuff.
 
 Dave
 
 -- 
 David Young
 dyoung%pobox.com@localhost    Urbana, IL    (217) 721-9981