kern/156667: em0 fails to init on CURRENT after March 17

[Marcus Reid]

>Number:         156667
>Category:       kern
>Synopsis:       em0 fails to init on CURRENT after March 17
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Apr 27 04:00:18 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Marcus Reid
>Release:        9.0-CURRENT
>Organization:
>Environment:
FreeBSD austin 9.0-CURRENT FreeBSD 9.0-CURRENT #0: Tue Apr 26 20:27:12 PDT 2011     root at austin:/usr/obj/usr/src/sys/FARK  amd64

kernel / world compiled with clang.
>Description:
em0 fails to init on kernel csupped and built on Apr 26, 2011, but is fine on kernel built on Mar. 17, 2011.

Messages before:

Mar 17 23:08:09 austin kernel: em0: <Intel(R) PRO/1000 Network Connection 7.1.9> port 0xecc0-0xecdf mem 0xfebe0000-0xfebfffff,0xfebdb000-0xfebdbfff irq 21 at device 25.0 on pci0
Mar 17 23:08:09 austin kernel: em0: Using an MSI interrupt
Mar 17 23:08:09 austin kernel: em0: Ethernet address: 00:1e:4f:e7:f6:51

Messages after:

Apr 26 19:35:59 austin kernel: em0: <Intel(R) PRO/1000 Network Connection 7.2.3> port 0xecc0-0xecdf mem 0xfebe0000-0xfebfffff,0xfebdb000-0xfebdbfff irq 21 at device 25.0 on pci0
Apr 26 19:35:59 austin kernel: em0: Using an MSI interrupt
Apr 26 19:35:59 austin kernel: em0: Ethernet address: 00:1e:4f:e7:f6:51
Apr 26 19:35:59 austin kernel: em0: Could not setup receive structures
Apr 26 19:35:59 austin kernel: em0: Could not setup receive structures
Apr 26 19:36:04 austin kernel: em0: link state changed to UP
Apr 26 19:36:04 austin kernel: em0: Could not setup receive structures

pciconf -vl:

em0 at pci0:0:25:0:        class=0x020000 card=0x02111028 chip=0x10bd8086 rev=0x02 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Intel 82566DM Gigabit Ethernet Adapter (82566DM)'
    class      = network
    subclass   = ethernet

System is a Dell Optiplex 755 using onboard ethernet.

There were a number of changes, some major, since Apr 26.
>How-To-Repeat:
Boot, network interface doesn't seem to work.  No arp from default gateway, etc.
>Fix:


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