Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Mime-Version: 1.0
Subject: RE: Re: [PATCH v16 1/3] scsi: ufs: Introduce HPB feature
Reply-To: daejun7.park@samsung.com
Sender: Daejun Park <daejun7.park@samsung.com>
From:   Daejun Park <daejun7.park@samsung.com>
To:     Greg KH <gregkh@linuxfoundation.org>,
        Avri Altman <Avri.Altman@wdc.com>
CC:     Daejun Park <daejun7.park@samsung.com>,
        "jejb@linux.ibm.com" <jejb@linux.ibm.com>,
        "martin.petersen@oracle.com" <martin.petersen@oracle.com>,
        "asutoshd@codeaurora.org" <asutoshd@codeaurora.org>,
        "stanley.chu@mediatek.com" <stanley.chu@mediatek.com>,
        "cang@codeaurora.org" <cang@codeaurora.org>,
        "huobean@gmail.com" <huobean@gmail.com>,
        "bvanassche@acm.org" <bvanassche@acm.org>,
        ALIM AKHTAR <alim.akhtar@samsung.com>,
        "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Sung-Jun Park <sungjun07.park@samsung.com>,
        yongmyung lee <ymhungry.lee@samsung.com>,
        Jinyoung CHOI <j-young.choi@samsung.com>,
        Adel Choi <adel.choi@samsung.com>,
        BoRam Shin <boram.shin@samsung.com>,
        SEUNGUK SHIN <seunguk.shin@samsung.com>
In-Reply-To: <X934OOlXSf5up8Rd@kroah.com>
Message-ID: <20201221023407epcms2p1e5aaaff4fffcee73a0ecf422b078e888@epcms2p1>
Date:   Mon, 21 Dec 2020 11:34:07 +0900
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="utf-8"
CMS-TYPE: 102P
DLP-Filter: Pass
References: <X934OOlXSf5up8Rd@kroah.com>
        <20201219091802epcms2p2c86f7ae2e81aa015702572a8ef180dae@epcms2p2>
        <20201219091847epcms2p7afeebd03c47eed0b65f89375a881233e@epcms2p7>
        <X93XuJ4lsQbBgnU+@kroah.com>
        <DM6PR04MB6575AC2A541FCAAB60E581FBFCC20@DM6PR04MB6575.namprd04.prod.outlook.com>
        <CGME20201219091802epcms2p2c86f7ae2e81aa015702572a8ef180dae@epcms2p1>
Precedence: bulk

Hi Greg, Avri

> On Sat, Dec 19, 2020 at 12:48:31PM +0000, Avri Altman wrote:
> > > 
> > > 
> > > On Sat, Dec 19, 2020 at 06:18:47PM +0900, Daejun Park wrote:
> > > > +static int ufshpb_get_state(struct ufshpb_lu *hpb)
> > > > +{
> > > > +     return atomic_read(&hpb->hpb_state);
> > > > +}
> > > > +
> > > > +static void ufshpb_set_state(struct ufshpb_lu *hpb, int state)
> > > > +{
> > > > +     atomic_set(&hpb->hpb_state, state);
> > > > +}
> > > 
> > > You have a lock for the state, and yet the state is an atomic variable
> > > and you do not use the lock here at all.  You don't use the lock at all
> > > infact...
> > > 
> > > So either the lock needs to be dropped, or you need to use the lock and
> > > make the state a normal variable please.
> > hpb_state_lock is mainly protecting the list of active regions.
> > Just grep  lh_lru_rgn in patch 2/3.
> 
> Then why is the lock added in this patch if it is not used here?

I think it comes from that the name of the lock and related comment is
different from the actual usage.
I will modify the name and related comments, and introduce the lock to the
patch 2/3.

Thanks,
Daejun