kern/159296: em watchdog timeouts

[Kurt Jaeger]

>Number:         159296
>Category:       kern
>Synopsis:       em watchdog timeouts
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Jul 29 14:30:14 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Kurt Jaeger
>Release:        FreeBSD 8.2-STABLE i386
>Organization:
-
>Environment:
System: FreeBSD gk-intern.nepustil.net 8.2-STABLE FreeBSD 8.2-STABLE #0: Thu Jul 28 16:46:30 UTC 2011 pi at gk-intern.nepustil.net:/usr/obj/usr/src/sys/GENERIC i386

>Description:

Jul 29 09:11:58 gk-intern kernel: em4: Watchdog timeout -- resetting
Jul 29 09:11:58 gk-intern kernel: wan0: link state changed to DOWN
Jul 29 09:12:00 gk-intern kernel: wan0: link state changed to UP

em0 at pci0:1:0:0: class=0x020000 card=0x00008086 chip=0x10d38086 rev=0x00 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Intel 82574L Gigabit Ethernet Controller (82574L)'
    class      = network
    subclass   = ethernet
    bar   [10] = type Memory, range 32, base 0xfd9c0000, size 131072, enabled
    bar   [18] = type I/O Port, range 32, base 0x9f00, size 32, enabled
    bar   [1c] = type Memory, range 32, base 0xfd9fc000, size 16384, enabled

[...]

em4 at pci0:5:10:0:        class=0x020000 card=0x10768086 chip=0x10768086 rev=0x05 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Gigabit Ethernet Controller (82541EI)'
    class      = network
    subclass   = ethernet
em5 at pci0:5:11:0:        class=0x020000 card=0x10768086 chip=0x10768086 rev=0x05 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Gigabit Ethernet Controller (82541EI)'
    class      = network
    subclass   = ethernet

There are other em interfaces in this box, but they do not have
the timeout problem:

dev.em.0.%desc: Intel(R) PRO/1000 Network Connection 7.2.3
dev.em.1.%desc: Intel(R) PRO/1000 Network Connection 7.2.3
dev.em.2.%desc: Intel(R) PRO/1000 Network Connection 7.2.3
dev.em.3.%desc: Intel(R) PRO/1000 Network Connection 7.2.3
dev.em.4.%desc: Intel(R) PRO/1000 Legacy Network Connection 1.0.3
dev.em.5.%desc: Intel(R) PRO/1000 Legacy Network Connection 1.0.3

Why are em4 and 5 using the Legacy ?

>How-To-Repeat:
	Good question! It happens a few times a day

>Fix:

	no solution as of now.


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