kern/131738: [re] re0: watchdog timeout (missed Tx interrupts) -- recovering

[Trevor Roydhouse]

>Number:         131738
>Category:       kern
>Synopsis:       [re] re0: watchdog timeout (missed Tx interrupts) -- recovering
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Feb 16 09:30:01 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator:     Trevor Roydhouse
>Release:        7.1-STABLE
>Organization:
Sentry
>Environment:
FreeBSD xxxx.xxx.org 7.1-STABLE FreeBSD 7.1-STABLE #16: Wed Feb 11 18:49:36 EST 2009     xxxxxx at xxxx.xxx.org:/usr/obj/usr/src/sys/SHADOW  amd64
>Description:
Hardware: 
Gigabyte MA790X-DS4 AMD motherboard with onboard RealTek 8111B PCI-E Gigabit NIC;
Phenom 9550 quad core CPU;
4Gb RAM.

if_re details:
$FreeBSD: src/sys/dev/re/if_re.c,v 1.95.2.41 2009/02/09 01:38:01 yongari Exp $

if_rlreg details:
$FreeBSD: src/sys/pci/if_rlreg.h,v 1.67.2.20 2009/02/09 01:38:01 yongari Exp $

pciconf -lv output:
re0 at pci0:2:0:0: class=0x020000 card=0xe0001458 chip=0x816810ec rev=0x01 hdr=0x00
    vendor     = 'Realtek Semiconductor'
    device     = 'RTL8168/8111 PCI-E Gigabit Ethernet NIC'
    class      = network
    subclass   = ethernet

dmesg:
re0: <RealTek 8168/8168B/8168C/8168CP/8168D/8111B/8111C/8111CP PCIe Gigabit Ethernet> port 0xee00-0xeeff mem 0xfdfff000-0xfdffffff irq 18 at device 0.0 on pci2
re0: turning off MSI enable bit.
re0: Chip rev. 0x38000000
re0: MAC rev. 0x00000000
miibus0: <MII bus> on re0
rgephy0: <RTL8169S/8110S/8211B media interface> PHY 1 on miibus0
rgephy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 1000baseT-FDX, auto
re0: Ethernet address: 00:1f:d0:a4:ec:fc
re0: [FILTER]

messages log entries:
Feb 15 17:37:05 shadow kernel: re0: watchdog timeout (missed Tx interrupts) -- recovering
Feb 15 19:49:52 shadow kernel: re0: watchdog timeout (missed Tx interrupts) -- recovering

The watchdog timeouts occur intermittently, possibly during periods of high outbound bandwidth utilisation (1 Mbps DSL outbound/20 Mbps DSL inbound).
>How-To-Repeat:
Intermittent :-(  

ftp from one LAN gigabit machine to/from this system via a gigabit switch does not cause the issue. Tx throughput approaches 35 Mbps. Yet timeouts occur when serving external web clients via the gigabit switch, connected to the 100 Mbps port of a Siemens Speedstream 4200 ADSL router on an ADSL2+ line (20 Mbps down, 1 Mbps up).
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: