From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751817AbcFVGvc (ORCPT ); Wed, 22 Jun 2016 02:51:32 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:11822 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751013AbcFVGv2 (ORCPT ); Wed, 22 Jun 2016 02:51:28 -0400 Subject: Re: [PATCH v10 06/22] IB/hns: Add initial cmd operation To: References: <1466087730-54856-1-git-send-email-oulijun@huawei.com> <1466087730-54856-7-git-send-email-oulijun@huawei.com> <20160620133310.GB4526@leon.nu> <57691C0B.8090509@huawei.com> <20160621112808.GA9762@leon.nu> <57693AC4.1070306@huawei.com> <20160622045450.GC9762@leon.nu> CC: Lijun Ou , , , , , , , , , , , , , , , , , , From: "Wei Hu (Xavier)" Message-ID: <576A352F.8000700@huawei.com> Date: Wed, 22 Jun 2016 14:50:23 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <20160622045450.GC9762@leon.nu> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.57.115.113] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090206.576A353F.0095,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 8b5632540a22da903e5f9ce4ee286a78 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016/6/22 12:54, Leon Romanovsky wrote: > On Tue, Jun 21, 2016 at 09:01:57PM +0800, Wei Hu (Xavier) wrote: >> >> On 2016/6/21 19:28, Leon Romanovsky wrote: >>> On Tue, Jun 21, 2016 at 06:50:51PM +0800, Wei Hu (Xavier) wrote: >>>> On 2016/6/20 21:33, Leon Romanovsky wrote: >>>>> On Thu, Jun 16, 2016 at 10:35:14PM +0800, Lijun Ou wrote: >>>>>> This patch added the operation for cmd, and added some functions >>>>>> for initializing eq table and selecting cmd mode. >>>>>> >>>>>> Signed-off-by: Wei Hu >>>>>> Signed-off-by: Nenglong Zhao >>>>>> Signed-off-by: Lijun Ou >>>>>> --- >>>>>> PATCH v9/v8/v7/v6: >>>>>> - No change over the PATCH v5 >>>>>> >>>>>> PATCH v5: >>>>>> - The initial patch which was redesigned based on the second patch >>>>>> in PATCH v4 >>>>>> --- >>>>> <...> >>>>> >>>>>> +#define CMD_MAX_NUM 32 >>>>>> + >>>>>> +int hns_roce_cmd_init(struct hns_roce_dev *hr_dev) >>>>>> +{ >>>>>> + struct device *dev = &hr_dev->pdev->dev; >>>>>> + >>>>>> + mutex_init(&hr_dev->cmd.hcr_mutex); >>>>>> + sema_init(&hr_dev->cmd.poll_sem, 1); >>>>>> + hr_dev->cmd.use_events = 0; >>>>>> + hr_dev->cmd.toggle = 1; >>>>>> + hr_dev->cmd.max_cmds = CMD_MAX_NUM; >>>>> <...> >>>>> >>>>>> + for (hr_cmd->token_mask = 1; hr_cmd->token_mask < hr_cmd->max_cmds; >>>>>> + hr_cmd->token_mask <<= 1) >>>>>> + ; >>>>>> + --hr_cmd->token_mask; >>>>> It doesn't look that you dynamically change max_cmds supported. >>>>> Why do you need to calculate token_mask dynamically? >>>> Hi, Leon >>>> >>>> 1. The four lines above are in the function named >>>> hns_roce_cmd_use_events. >>>> and now this function is only called once in hns_roce_probe. >>>> 2. In hns_roce_cmd_use_events, >>>> we use these 4 lines to achieve the value of hr_cmd->token_mask >>>> according to hr_cmd->max_cmds dynamically, >>>> then we only define one marco for hr_cmd->max_cmds as below: >>>> >>>> #define CMD_MAX_NUM 32 >>>> >>>> And it looks more flexible. >>> It is called over engineering. >>> I would recommend to you to remove it. >>> >>> We don't need over complicated code which is executed >>> once with need to maintain with zero benefit. >>> >>> The other places need such simplification too. >> Hi, Leon >> >> We will modify this place as below: >> In hns_roce_hw_v1.c(for hip06 soc) file: >> >> void hns_roce_v1_profile(struct hns_roce_dev *hr_dev) >> { >> >> caps->max_cmds = 32; >> >> } >> >> In hns_roce_cmd.c file: >> >> int hns_roce_cmd_init(struct hns_roce_dev *hr_dev) >> { >> >> hr_dev->cmd.max_cmds = hr_dev->caps->max_cmds; >> >> } >> >> Can you give more suggestions? > I would be happy to do it if I had enough time to review this code. > > General suggestion will be to ask yourself, if value is going to be > changed during the runtime. In case the answer is no, there is no room > to additional logic which translate constant to different value which > will be other constant. > > You should do it across all the patchset. > > So, in this specific case, the proposed change is not enough, you are > not solving an issue, but hiding it. > > Thanks We will modify this place as below： #define CMD_TOKEN_MASK 0x1f hr_cmd->token_mask = CMD_TOKEN_MASK; delete these four lines: for (hr_cmd->token_mask = 1; hr_cmd->token_mask < hr_cmd->max_cmds; hr_cmd->token_mask <<= 1) ; --hr_cmd->token_mask; Thanks >> >> Regards >> Wei Hu >>>> Regards >>>> Wei Hu >>>> >>>> >>>> >>