Mellanox CX6 and nvmet connectivity failure, happens on RHEL9.2 kernels and latest 6.6 upstream

[Chaitanya Kulkarni]

>>> Hi MArk
>>>
>>> I landed up changing the default kato from 5s to 30 and its working
>>> now
>>> We don't jump ship too early anymore and it connects fine.
>>> See prior response where I answered my own message
>>>
>>> diff -Nurp linux-5.14.0-
>>> 284.25.1.el9_2.orig/drivers/nvme/host/nvme.h
>>> linux-5.14.0-284.25.1.el9_2/drivers/nvme/host/nvme.h
>>> --- linux-5.14.0-
>>> 284.25.1.el9_2.orig/drivers/nvme/host/nvme.h   2023-
>>> 07-20 08:42:08.000000000 -0400
>>> +++ linux-5.14.0-
>>> 284.25.1.el9_2/drivers/nvme/host/nvme.h        2023-
>>> 11-08 14:16:37.924155469 -0500
>>> @@ -25,7 +25,7 @@ extern unsigned int nvme_io_timeout;
>>>   extern unsigned int admin_timeout;
>>>   #define NVME_ADMIN_TIMEOUT     (admin_timeout * HZ)
>>>   
>>> -#define NVME_DEFAULT_KATO      5
>>> +#define NVME_DEFAULT_KATO      30
>>>   
>>>   #ifdef CONFIG_ARCH_NO_SG_CHAIN
>>>   #define  NVME_INLINE_SG_CNT  0
>>>
>>>
>>> I will wait for Sagi and Keith and then send a patch
>>> I had the wrong email for Keith
>>>
>>> Thanks a lot
>>> Laurence
>>>

yes, we really don't need above patch as -k connect should take of that
as mentioned below, seems like it got revolve ...

>> Hello
>>
>> No fix needed, I was unaware of the -k option in the nvme connect.
>> My colleague showed it to me.
>> This works now to give the CX6 longer to handle the connection
>>
>> #!/bin/bash
>> modprobe nvme-fc
>> nvme connect -t rdma -n nqn.2023-10.org.dell -a  172.18.60.2  -s 4420
>> -
>> k 30
>>
>>
>> Thanks
>> So a Heads up for these newer cards I guess, need more time
>>
>> Regards
>> Laurence
>>
>>
>>
>>
>>
> Finalizing this discussion and adding appropriate cc's
>
>
> No patch needed, I was unaware of the -k option in the nvme connect.
> My colleague John Pittman showed it to me. and in fact Mark also
> pointed it out in a follow up email.
> This works now to give the CX6 longer to handle the connection.
> C.K Thanks to you as well for responding
>
> Initiator
> #!/bin/bash
> modprobe nvme-fc
> nvme connect -t rdma -n nqn.2023-10.org.dell -a  172.18.60.2  -s 4420
> -k 30
>
> Thanks
> So a Heads up for these newer cards I guess, need more time
>
> Learn something new every day
>

-ck