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;
Message-ID: <a2338ef6da3d4ed4093547ba87e13e94d8dd2a45.camel@gmail.com>
Subject: Re: [PATCH 1/2] scsi: ufs: Protect some contexts from unexpected
 clock scaling
From:   Bean Huo <huobean@gmail.com>
To:     Can Guo <cang@codeaurora.org>, asutoshd@codeaurora.org,
        nguyenb@codeaurora.org, hongwus@codeaurora.org,
        rnayak@codeaurora.org, linux-scsi@vger.kernel.org,
        kernel-team@android.com, saravanak@google.com, salyzyn@google.com
Cc:     Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Stanley Chu <stanley.chu@mediatek.com>,
        Bean Huo <beanhuo@micron.com>,
        Bart Van Assche <bvanassche@acm.org>,
        Satya Tangirala <satyat@google.com>,
        open list <linux-kernel@vger.kernel.org>
Date:   Thu, 10 Dec 2020 18:34:49 +0100
In-Reply-To: <1607520942-22254-2-git-send-email-cang@codeaurora.org>
References: <1607520942-22254-1-git-send-email-cang@codeaurora.org>
         <1607520942-22254-2-git-send-email-cang@codeaurora.org>
Content-Type: text/plain; charset="UTF-8"
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Precedence: bulk

Hi Can

On Wed, 2020-12-09 at 05:35 -0800, Can Guo wrote:
> 
>  
> @@ -1160,6 +1166,7 @@ static void
> ufshcd_clock_scaling_unprepare(struct ufs_hba *hba)
>  {
>  	up_write(&hba->clk_scaling_lock);
>  	ufshcd_scsi_unblock_requests(hba);
> +	ufshcd_release(hba);
>  }
>  
>  /**
> @@ -1175,12 +1182,9 @@ static int ufshcd_devfreq_scale(struct ufs_hba
> *hba, bool scale_up)
>  {
>  	int ret = 0;
>  
> -	/* let's not get into low power until clock scaling is
> completed */
> -	ufshcd_hold(hba, false);
> -
>  	ret = ufshcd_clock_scaling_prepare(hba);
>  	if (ret)
> -		goto out;
> +		return ret;
>  
>  	/* scale down the gear before scaling down clocks */
>  	if (!scale_up) {
> @@ -1212,8 +1216,6 @@ static int ufshcd_devfreq_scale(struct ufs_hba
> *hba, bool scale_up)
>  
>  out_unprepare:
>  	ufshcd_clock_scaling_unprepare(hba);
> -out:
> -	ufshcd_release(hba);
>  	return ret;
>  }

I didn't understand why moving ufshcd_hold/ufshcd_release into
ufshcd_clock_scaling_prepare()/ufshcd_clock_scaling_unprepare().


>  
> @@ -1294,15 +1296,8 @@ static int ufshcd_devfreq_target(struct device
> *dev,
>  	}
>  	spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
>  
> -	pm_runtime_get_noresume(hba->dev);
> -	if (!pm_runtime_active(hba->dev)) {
> -		pm_runtime_put_noidle(hba->dev);
> -		ret = -EAGAIN;
> -		goto out;
> -	}
>  	start = ktime_get();
>  	ret = ufshcd_devfreq_scale(hba, scale_up);
> -	pm_runtime_put(hba->dev);
>  

which branch are you working on?  I didn't see this part codes in the
branch 5.11/scsi-queue and 5.11/scsi-staging.

Bean