em broken on current amd64

[Mark R V Murray]

> On 8 Sep 2015, at 19:02, Mark R V Murray <markm at FreeBSD.org> wrote:
> 
> 
>> On 8 Sep 2015, at 17:22, Sean Bruno <sbruno at freebsd.org> wrote:
>> 
>> 
>>>>> 
>>>>> I’m also seeing breakage with the em0 device; this isn’t a kernel
>>>>> hang, it is a failure to move data after about 10-15 minutes. The
>>>>> symptom is that my WAN ethernet no longer moves traffic, no pings,
>>>>> nothing. Booting looks normal:
>>>>> 
>>>>> em0: <Intel(R) PRO/1000 Network Connection 7.4.2> port
>>>>> 0x30c0-0x30df mem 0x50300000-0x5031ffff,0x50324000-0x50324fff irq
>>>>> 20 at device 25.0 on pci0 em0: Using an MSI interrupt em0: Ethernet
>>>>> address: 00:16:76:d3:e1:5b em0: netmap queues/slots: TX 1/1024, RX
>>>>> 1/1024
>>>>> 
>>>>> Fixing it is as easy as …
>>>>> 
>>>>> # ifconfig em0 down ; service ipfw restart ; ifconfig em0 up
>>>>> 
>>>>> :-)
>>>>> 
>>>>> I’m running CURRENT, r287538. This last worked of me a month or so
>>>>> ago at my previous build.
>>>>> 
>>>>> M
>>>>> 
>>>> 
>>>> 
>>>> Just so I'm clear, the original problem reported was a failure to
>>>> attach (you were among several folks reporting breakage).  Is that fixed
>>>> ?
>>> 
>>> I did not report the failure to attach, and I am not seeing it as I don’t
>>> think I built a kernel that had that particular failure. I am having the
>>> “failure after 10-15 minutes” problem; this is on an em0 device.
>>> 
>>> M
>>> 
>> 
>> 
>> Hrm, that's odd.  That sounds like a hole where interrupts aren't being
>> reset for "reasons" that I cannot fathom.
>> 
>> What hardware (pciconf -lv) does your system actually have?  The em(4)
>> driver doesn't identify components which is frustrating.
> 
> pciconf -lv output below:
> 
> hostb0 at pci0:0:0:0:	class=0x060000 card=0x514d8086 chip=0x29a08086 rev=0x02 hdr=0x00
>    vendor     = 'Intel Corporation'
>    device     = '82P965/G965 Memory Controller Hub'
>    class      = bridge
>    subclass   = HOST-PCI

I just caught this, on today’s build:

em0: Watchdog timeout Queue[0]-- resetting
Interface is RUNNING and ACTIVE
em0: TX Queue 0 ------
em0: hw tdh = 127, hw tdt = 139
em0: Tx Queue Status = -2147483648
em0: TX descriptors avail = 1012
em0: Tx Descriptors avail failure = 0
em0: RX Queue 0 ------
em0: hw rdh = 0, hw rdt = 1023
em0: RX discarded packets = 0
em0: RX Next to Check = 0
em0: RX Next to Refresh = 1023

[graveyard] /usr/ports 09:42 pm # uname -a
FreeBSD graveyard.grondar.org 11.0-CURRENT FreeBSD 11.0-CURRENT #0 r287705: Sat Sep 12 15:07:54 BST 2015     root at graveyard.grondar.org:/b/obj/usr/src/sys/G_AMD64_GATE  amd64

M
-- 
Mark R V Murray