Initialized State

Under Software Control, Initialized Is Entered From...

...the Reset state. Software transitions a QP from the Reset state to the Initialized state using the Modify QP verb call.

Initialized State Operational Characteristics

When a QP is in the Initialized state, it has the following operational characteristics:

  • WRs can be posted to the RQ, but they are not processed.

  • Incoming packets targeting QP's RQ are silently dropped.

  • Any attempt to post a WR to the SQ results in the return of an immediate error.

  • WRs on the SQ are not processed.

  • Other than executing the Destroy QP verb call, the Modify QP verb call is the only way software can cause transition the QP out of the Initialize state. The next state must be the RTR state.

  • If it is an RD QP and software attempts to post a WR that specifies an EEC currently in the Initialized state to the SQ of a RD QP, the WR is completed in error.

Next State (via software command) = RTR

From the Initialized state, the only valid state that software may transition the QP to is the Ready To Receive (RTR) state. To do so, software executes the Modify QP verb call and supplies the input parameters defined in Table 12-3 on this page. Note that using the Modify QP verb, software can command the QP to enter the Reset or the Error state.

Table 12-3. Initialized-to-RTR Modify QP Input Parameters
Input Parameter(s)Applicable QP TypesRequired?Description
HCA HandleAllYesReturned by earlier Open HCA verb call.
QP HandleAllYesReturned by earlier Create QP verb call.
Next StateAllYesIn this case, the RTR state.
RQ's Start ePSNRC and UCYesThe RQ Logic 's Start ePSN must be set to the Start PSN assigned to the remote QP's SQ Logic. It is supplied in the REP message during the connection establishment process.
Queue depth for inbound RDMA Read/Atomic operationsRC and RDYesDepth of the special queue in the RQ Logic into which inbound RDMA Read and atomic operation requests are received.
Remote Node Address VectorRC and UCYesSoftware provides the QP with all of the address information necessary to send packets to the remote CA port that the destination QP resides behind. This includes:

  • Service Level (SL).

  • Send GRH Flag. If set, indicates remote CA is in a different subnet and packets sent to it must include a GRH. In that case, software also provides the following:

    - Traffic Class.

    - Flow Label.

    - Hop Limit.

    - Source GID index.

    - DGID.

  • DLID. If destination CA is in the same subnet, DLID = destination CA port LID; otherwise DLID = LID of a router ingress port.

  • Path MTU.

  • Maximum Static Rate.

  • Local ACK Timeout (RC only).

  • Retry Count (RC only).

  • RNR Retry Count (RC only).

  • Source Path Bits.

Please note that, although Retry Count and RNR Retry Count are both shown as Alternate Path address information in the 1.0a specification, their removal from this list has been approved for the next specification revision.
Destination QPNRC and UCYesSelf-explanatory.
Alternate Path Address InformationRC and UCNoIf HCA supports Automatic Path Migration, software may optionally supply:

  • Alternate path P_Key index.

  • Alternate path HCA port for this QP to use.

  • Alternate path address vector, containing all of the information specified in this table's description for Remote Node Address Vector (but for a different path, of course).

Enable/disable incoming RDMA and Atomic OperationsRC, RD, UCNo

  • Enable/disable incoming RDMA Reads on this QP (only for RC and RD).

  • Enable/disable incoming RDMA Writes on this QP.

  • Enable/disable incoming Atomic operations on this QP (only for RC and RD).

Primary P_Key indexRC, UC, UDNoSee the description of the Primary P_Key index parameter in Table 12-2 on page 238.
Q_KeyUD and RDNoSee the description of the Q_Key parameter in Table 12-2 on page 238.
New SQ and/or RQ sizeAllNoIf HCA supports resizing of the SQ and RQ:

  • Maximum number of outstanding WRs software expects to post to SQ.

  • Maximum number of outstanding WRs software expects to post to RQ.

Minimum RNR Nak Timer Field RC and RDNoIf an inbound Send or RDMA Write With Immediate message arrives when no WQEs are posted to the RQ, the RQ Logic responds with an RNR Nak. This is the value that is placed in the Nak packet's RNR Nak Timer Field. The packet sender must wait at least this amount of time before attempting to resend the request packet again.

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