[openib-general] APM support in openib stack

[somenath]

Sean Hefty wrote:

>>3. in req_handler() we follow the same steps as we have done without APM..
>>  i.e. create qpairs, change qp state to RTR and then  send REP.
>>
>>however, when trying to change state to RTR usinb ib_modify_qp() I get
>>an error (-22).
>>
>>two info: same code will work if I pass alt_path as NULL or change the
>>alt_path as primary path.
>>
>>I must be missing something here, I assume this basic APM feature works
>>in RHEL4 update 4 distribtion
>>of openib stack.
>>    
>>
>
>I added code to the ib_cm to handle APM, but haven't ever tested it myself.  I
>believe others have used it successfully though.
>
>What differences are there between the primary and alternate paths?  I.e. are
>just the LIDs different, or are other values also different?
>
>- Sean
>  
>
Sean:

thanks for ur reply.
I use
 ib_sa_path_rec_get(
                    device,
                    HCA_PRM_PORT,           /* first port =1, second 
port=2 */
                    &path_rec,
                    IB_SA_PATH_REC_DGID | IB_SA_PATH_REC_SGID |
                    IB_SA_PATH_REC_NUMB_PATH
                    | IB_SA_PATH_REC_PKEY,
                    5000,
                    GFP_KERNEL,
                    func_completion,
                    context,
                    &query)

to get the primary path, and make the same call with HCA_ALT_PORT (=2) to
get the alternate path.

primary path has the source and destination gid for the HCA port 1,
alternate path the source and destination gid for the HCA port 2.

using these two paths, I send the REQ, otherwise gets the REQ...
(I can dump the primary and alternate path received in req handler to check
everything is ok, will try that next..)

do you remember when you checked in the working code?
I am wondering if the RHEL4 U4 binary distrition of redhat has your changes.

thanks, som.