Re: bge/brg: no carrier after cable disconnect/reconnect

[Sverre Froyen <sverre%viewmark.com@localhost>]

> On 2015-01-06, at 21:14, Masanobu SAITOH <msaitoh%execsw.org@localhost> wrote:
> 
> Hello, Sverre.
> 
> On 2015/01/06 5:33, Sverre Froyen wrote:
>> Hi,
>> 
>> I was performing some network maintenance and noticed that after disconnecting and reconnecting bge/brgphy interfaces, the interfaces are stuck in a “no carrier” state. I’m pretty sure this used not to be case but I have no idea how long ago that was. It appears that the only way to revive a stuck interface it to reboot the computer.
>> 
>> Here’s some data for the computer:
>> 
>> NetBSD 6.1_STABLE (VM) #12: Fri Jan  2 09:32:36 MST 2015
>> Dell Computer Corporation PowerEdge 2650
>> 
>> bge0 at pci1 dev 6 function 0: Broadcom BCM5701 Gigabit Ethernet
>> bge0: interrupting at ioapic1 pin 12
>> bge0: HW config 00000019, 00000000, 00000000, 00000000 00000000
>> bge0: ASIC BCM5701 B5 (0x105), Ethernet address 00:06:5b:fd:79:a6
>> brgphy0 at bge0 phy 1: BCM5701 1000BASE-T media interface, rev. 0
>> brgphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 1000baseT-FDX, auto
>> 
>> The interface is connected (twisted pair) to a 100Mb/s switch (also Dell).
>> 
>> The sources were updated 2 Jan.
>> 
>> ifconfig output (in the running state):
>> 
>> bge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>> 	capabilities=3f00<IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx,TCP4CSUM_Tx,UDP4CSUM_Rx,UDP4CSUM_Tx>
>> 	enabled=3f00<IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx,TCP4CSUM_Tx,UDP4CSUM_Rx,UDP4CSUM_Tx>
>> 	address: xx:xx:xx:xx:xx:xx
>> 	media: Ethernet autoselect (100baseTX full-duplex,flowcontrol,rxpause,txpause)
>> 	status: active
>> 	inet xxx.xxx.xxx.xxx netmask 0xffffffc0 broadcast xxx.xxx.xxx.xxx
>> 	inet6 fe80::206:5bff:fefd:79a6%bge0 prefixlen 64 scopeid 0x1
>> 
>> I believe this also happens with bnx/brgphy interfaces (on amd64).
>> 
>> Any suggestions?
> 
> It might be my fault. If the problem is caused by brgphy, one of
> a way to debug is to comment out brgphy entry from your kernel
> configuration file to use ukphy. Could you try it?
> 
> Thanks.


Booting a kernel without brgphy restores the expected behavior (status returns to active when cable reattached). Here’s the corresponding dmsg output:

bge0 at pci1 dev 6 function 0: Broadcom BCM5703X Gigabit Ethernet
bge0: interrupting at ioapic1 pin 12
bge0: HW config 00000115, 00000000, 00000000, 00000000 00000000
bge0: ASIC BCM5702/5703 A2 (0x1002), Ethernet address 00:0f:1f:6e:f3:2d
ukphy0 at bge0 phy 1: OUI 0x001018, model 0x0016, rev. 2
ukphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 1000baseT-FDX, auto

(I tested this on a another computer but I verified that its brgphy behavior was the same as the one I used above.)

I also dug some old kernels out of my backups. It looks like a kernel from 2013-08-06 works OK and one from 2013-11-28 fails. Sources were cvs updated from the netbsd-6 branch on or shortly before those dates.

Please let me know what I can do to help track this down.

Thanks,
Sverre