***SPAM*** Re: ***SPAM*** Re: [ofa-general] link width problem of Qlogic 9024 unmanaged switch

[Hal Rosenstock]

On Fri, Apr 17, 2009 at 1:44 PM, Ira Weiny <weiny2 at llnl.gov> wrote:
> On Fri, 17 Apr 2009 12:06:43 -0500
> Yicheng Jia <YJia at tmriusa.com> wrote:
>
>> Hi Ira,
>>
>> Here is the output of "iblinkinfo.pl -R":
>>
>> ++++++++++++++++++++++++++++++++++++++++++++++++
>> [root at ib_manager ~]# iblinkinfo.pl -R
>> Switch 0x00066a00d90009c1 InfiniCon System InfinIO 9024 Lite:
>>       7    1[  ]  ==( 4X 2.5 Gbps Active /   LinkUp)==>       6    1[  ] "MT2520 4 InfiniHostLx Mellanox Technologies" (  )
>>            2[  ]  ==( 4X 2.5 Gbps   Down /  Polling)==>             [  ] "" (  )
>>            3[  ]  ==( 4X 2.5 Gbps   Down /  Polling)==>             [  ] "" (  )
>>            4[  ]  ==( 4X 2.5 Gbps   Down /  Polling)==>             [  ] "" (  )
>
> [snip]
>
>>
>> And the "ibstat" output:
>> +++++++++++++++++++++++++++++++++++
>> [root at ib_manager ~]# ibstat
>> CA 'mthca0'
>>         CA type: MT25204
>>         Number of ports: 1
>>         Firmware version: 1.2.0
>>         Hardware version: a0
>>         Node GUID: 0x0002c90200230784
>>         System image GUID: 0x0002c90200230787
>>         Port 1:
>>                 State: Active
>>                 Physical state: LinkUp
>>                 Rate: 10
>>                 Base lid: 6
>>                 LMC: 0
>>                 SM lid: 6
>>                 Capability mask: 0x02500a6a
>>                 Port GUID: 0x0002c90200230785
>> ++++++++++++++++++++++++++++++++++++++++++++++
>>
>> The reset command I am using is "ibportstate 7 1 reset", I also tried
>> "ibportstate -D 0,1 1 reset", and it fails with the same result.
>>
>
> Yea that is going to be a problem.  The problem is that effectively you just
> disabled the connection to the switch.

That was Nicolas' original point and what I wrote before was wrong:
disable really does disable the link and it doesn't come back to init
so things are behaving as expected.

> A reset disables then enables the
> port.  Once the port is disabled the command can't talk to the switch any
> longer.

Yes, in this configuration, you've shot yourself in the foot. Guess we
could check for this case too and not allow it.

> You will have to either reset the switch (power cycle) or go to
> another node and enable the port.

That's usually how its down (from another port so switch connectivity
isn't lost).

-- Hal

> From the output you sent me it looks like
> you don't have any other nodes on the switch, so I take it you are resetting
> the switch to get the link to come back?
>
> I thought there was a warning in the man page or in the help regarding this
> situation but I don't see it now.
>
> Also, this becomes worse if you disable the port the SM is on.  (Which I see
> you are doing.)  So you will have a noticeable delay while the SM rescans the
> network which it is now seeing "again" for the first time.
>
> BTW, What are you trying to achieve with this command?
>
> Hope this helps,
> Ira
>
>