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 v19 2/3] scsi: ufs: L2P map management for HPB read
Reply-To: daejun7.park@samsung.com
Sender: Daejun Park <daejun7.park@samsung.com>
From:   Daejun Park <daejun7.park@samsung.com>
To:     Can Guo <cang@codeaurora.org>,
        Daejun Park <daejun7.park@samsung.com>
CC:     Greg KH <gregkh@linuxfoundation.org>,
        "avri.altman@wdc.com" <avri.altman@wdc.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>,
        "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>,
        BoRam Shin <boram.shin@samsung.com>,
        SEUNGUK SHIN <seunguk.shin@samsung.com>
In-Reply-To: <5bd43da52369a56f18867fa18efb3020@codeaurora.org>
Message-ID: <20210208080333epcms2p59403f0acbc9730c9a605d265836a956d@epcms2p5>
Date:   Mon, 08 Feb 2021 17:03:33 +0900
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="utf-8"
CMS-TYPE: 102P
DLP-Filter: Pass
References: <5bd43da52369a56f18867fa18efb3020@codeaurora.org>
        <20210129052848epcms2p6e5797efd94e6282b76ad9ae6c99e3ab5@epcms2p6>
        <20210129053005epcms2p323338fbb83459d2786fc0ef92701b147@epcms2p3>
        <CGME20210129052848epcms2p6e5797efd94e6282b76ad9ae6c99e3ab5@epcms2p5>
Precedence: bulk

> @@ -342,13 +1208,14 @@ void ufshpb_suspend(struct ufs_hba *hba)
> >  	struct scsi_device *sdev;
> > 
> >  	shost_for_each_device(sdev, hba->host) {
> > -		hpb = sdev->hostdata;
> > +		hpb = ufshpb_get_hpb_data(sdev);
> >  		if (!hpb)
> >  			continue;
> > 
> >  		if (ufshpb_get_state(hpb) != HPB_PRESENT)
> >  			continue;
> >  		ufshpb_set_state(hpb, HPB_SUSPEND);
> > +		ufshpb_cancel_jobs(hpb);
> 
> Here may have a dead lock problem - in the case of runtime suspend,
> when ufshpb_suspend() is invoked, all of hba's children scsi devices
> are in RPM_SUSPENDED state. When this line tries to cancel a running
> map work, i.e. when ufshpb_get_map_req() calls below lines, it will
> be stuck at blk_queue_enter().
> 
> req = blk_get_request(hpb->sdev_ufs_lu->request_queue,
> 		      REQ_OP_SCSI_IN, 0);
> 
> Please check block layer power management, and see also commit d55d15a33
> ("scsi: block: Do not accept any requests while suspended").

I am agree with your comment.
How about add BLK_MQ_REQ_NOWAIT flag on blk_get_request() to avoid hang?

Thanks,
Daejun