[ofa-general] [PATCH] SRPT for current SCST

[Sufficool, Stanley]

I have updated to the most recent SRPT and applied the qp_max_atomic_res
patch to hard code to "4". The WinIB gen1 initiator now sees the target
without the error icon in Windows dev manager. However, WinIB still does
not show the LUNs/Drives and the Target is not even logging a login
attempt as it was before (Host i_port_id=...etc...). I have added debugs
throughout the code to notify of "ret != 0" and all seems to be well.

I will remove the max rdma patch and just swap out the target HCAs to
match the initiators. For consideration, can the target be made to "auto
negotiate" to the lowest capabilities of the initiator/target HCAs, and
perhaps throw a message when it does?


-----Original Message-----
From: Vu Pham [mailto:vu at mellanox.com] 
Sent: Wednesday, August 22, 2007 11:40 PM
To: Sufficool, Stanley
Cc: chas williams - CONTRACTOR; Stanley Sufficool; general
Subject: Re: [ofa-general] [PATCH] SRPT for current SCST

You can get hardware max rdma atomic by doing ib_query_qp

CM save the initiator's req->init_depth to its
cm_id_priv->responder_resources in cm_req_handler (Win's srp
  initiator set it at 16)

srpt call ib_cm_init_qp_attr() which will initialize
qp_attr->max_dest_rd_atomic = cm_id_priv->responder_resources = 16;

then srpt call ib_modify_qp() without checking/reseting the hw max rdma
atomic in qp_attr; therefore, ib_modify_qp() failed

You can try a quick dirty fix by applying this patch to ib_srpt.c

-vu




> So the client is requesting a QP with a max rdma_atomic of 15, but the

> target initializes the QP with a max of 4. Is this max rdma_atomic of 
> 4 based on hardware capabilities (Memory vs MemFree adapters), or a 
> target QP initialization preset value? I'll swap adapters if needed.
> 
> -----Original Message-----
> From: chas williams - CONTRACTOR [mailto:chas at cmf.nrl.navy.mil]
> Sent: Wednesday, August 22, 2007 4:28 AM
> To: Sufficool, Stanley
> Cc: Vu Pham; Stanley Sufficool; general
> Subject: Re: [ofa-general] [PATCH] SRPT for current SCST
> 
> In message
> <C2F174F99918D54CA2A96E57C5079B6F35504C at sbc-exmsg2.sbcounty.gov>,"Su
> fficool, Stanley" writes:
>> I'm still researching where the rdma_atomic is getting the invalid 
>> attribute. I will give an update if I find anything else.
> 
> srp clients set this value as the responder_resources during login i 
> believe.  this seems to be done in srp_get_responder_resources() on 
> the windows srp client.  its taken from the qp attributes instead of 
> picking a fixed number, like 4 in the linux version of the srp client.