On 2020/7/9 14:14, Gal Pressman wrote: > On 08/07/2020 18:44, Leon Romanovsky wrote: >> On Wed, Jul 08, 2020 at 03:42:34PM +0300, Gal Pressman wrote: >>> On 08/07/2020 12:41, liweihang wrote: >>>> Hi all, >>>> >>>> I'm a little confused about the role of IB_QP_CUR_STATE in the enumeration >>>> ib_qp_attr_mask. >>>> >>>> In manual page of ibv_modify_qp(), comments of cur_qp_state is "Assume this >>>> is the current QP state". Why we need to get current qp state from users >>>> instead of drivers? >>>> >>>> For example, why the users are allowed to modify qp from RTR to RTS again >>>> even if the qp's state in driver and hardware has already been RTS. >>>> >>>> I would be appretiate it if someone can help with this. >>>> >>>> Weihang >>>> >>> >>> Talking about IB_QP_CUR_STATE, I see many drivers filling it in their query QP >>> callback although it should only be used in modify operations.. Is there a >>> reason not to remove it? >> >> IBTA section "11.2.5.3 QUERY QUEUE PAIR" has line about IB_QP_CUR_STATE. >> It is one of output modifiers. >> >> Thanks >> > > It says the current QP state should be returned, that's what qp_state field is used for. > According to the man pages: > > libibverbs/man/ibv_query_qp.3: > enum ibv_qp_state qp_state; /* Current QP state */ > enum ibv_qp_state cur_qp_state; /* Current QP state - irrelevant for ibv_query_qp */ > Hi Gal and Leon, Thanks for your reply, as Gal said, I can't find the reason why the IBTA use cur_qp_state either. I'll take a closer look at the protocol. Weihang
