From: Gal Pressman <galpress@amazon.com>
To: Leon Romanovsky <leon@kernel.org>
Cc: liweihang <liweihang@huawei.com>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
Linuxarm <linuxarm@huawei.com>
Subject: Re: Question about IB_QP_CUR_STATE
Date: Thu, 9 Jul 2020 09:13:45 +0300 [thread overview]
Message-ID: <a738e3f3-e2bc-a670-7292-8025c78e210d@amazon.com> (raw)
In-Reply-To: <20200708154434.GA1276673@unreal>
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 */
next prev parent reply other threads:[~2020-07-09 6:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-08 9:41 Question about IB_QP_CUR_STATE liweihang
2020-07-08 12:20 ` Leon Romanovsky
2020-07-08 12:42 ` Gal Pressman
2020-07-08 15:44 ` Leon Romanovsky
2020-07-09 6:13 ` Gal Pressman [this message]
2020-07-10 10:11 ` liweihang
2020-07-12 10:44 ` Leon Romanovsky
2020-07-12 10:53 ` Gal Pressman
2020-07-12 11:01 ` Leon Romanovsky
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