Re: kern/50456: alc - packet loose when tcpdump

[Leonardo Taccari <leot%NetBSD.org@localhost>]

The following reply was made to PR kern/50456; it has been noted by GNATS.

From: Leonardo Taccari <leot%NetBSD.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/50456: alc - packet loose when tcpdump
Date: Sat, 21 Nov 2015 17:23:40 +0100

 Dear freddy,
 
 freddy.dsx+netbsd%free.fr@localhost writes:
 > >Number:         50456
 > >Category:       kern
 > >Synopsis:       alc - packet loose when tcpdump
 > >Confidential:   no
 > >Severity:       non-critical
 > >Priority:       low
 > >Responsible:    kern-bug-people
 > >State:          open
 > >Class:          sw-bug
 > >Submitter-Id:   net
 > >Arrival-Date:   Sat Nov 21 12:15:00 +0000 2015
 > >Originator:     freddy dissaux
 > >Release:        NetBSD 7.0
 > >Organization:
 > >Environment:
 > NetBSD n7010.bsdsx.fr 7.0 NetBSD 7.0 (GENERIC) #1: Sat Nov 21 13:36:17 C=
 ET 2015  root%n7010.bsdsx.fr@localhost:/usr/src/sys/arch/amd64/compile/
 > GENERIC amd64
 > =
 
 > >Description:
 > When tcpdump on alc, some packets are lost:
 > =
 
 > dsx@n7010>ping 172.16.40.1
 > PING 172.16.40.1 (172.16.40.1): 56 data bytes
 > 64 bytes from 172.16.40.1: icmp_seq=3D0 ttl=3D64 time=3D0.972398 ms
 > 64 bytes from 172.16.40.1: icmp_seq=3D1 ttl=3D64 time=3D0.921371 ms
 > # sudo tcpdump -n -i alc0 not port ssh
 > 64 bytes from 172.16.40.1: icmp_seq=3D8 ttl=3D64 time=3D1.025976 ms
 > 64 bytes from 172.16.40.1: icmp_seq=3D9 ttl=3D64 time=3D0.911102 ms
 > 64 bytes from 172.16.40.1: icmp_seq=3D10 ttl=3D64 time=3D0.948231 ms
 > # ^C tcpdump
 > 64 bytes from 172.16.40.1: icmp_seq=3D18 ttl=3D64 time=3D0.954294 ms
 > 64 bytes from 172.16.40.1: icmp_seq=3D19 ttl=3D64 time=3D0.907106 ms
 > ^C
 > ----172.16.40.1 PING Statistics----
 > 20 packets transmitted, 7 packets received, 65.0% packet loss
 > round-trip min/avg/max/stddev =3D 0.907106/0.948640/1.025976/0.041744 ms
 > >How-To-Repeat:
 > - configure an alc interface
 > - ping the gateway
 > - tcpdump on alc
 > >Fix:
 > Patch based on OpenBSD's sys/dev/pci/if_alc.c rev 1.36 follow
 Can you please try to backport from NetBSD-current to NetBSD 7.0 the
 following?:
 
  * src/sys/dev/pci/if_alc.c rev 1.15
  * src/sys/dev/pci/if_alcreg.h rev 1.4 =
 
 
 I think they will apply cleanly to NetBSD-7.0.
 Unfortunately during the porting from FreeBSD alc(4) I've missed some
 bits that I have only committed ~2 months ago (thanks to mrg@ and bad@
 for pointing out that!).
 
 Please let us know if it will solve the problems and I will request a
 pull-up for netbsd-7.
 
 
 Thank you in advance!
 L.