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Subject: Re: [PATCH v3 1/9] scsi: ufs: Differentiate status between hba pm ops
 and wl pm ops
To:     Can Guo <cang@codeaurora.org>, asutoshd@codeaurora.org,
        nguyenb@codeaurora.org, hongwus@codeaurora.org,
        ziqichen@codeaurora.org, linux-scsi@vger.kernel.org,
        kernel-team@android.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>,
        Jaegeuk Kim <jaegeuk@kernel.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Kiwoong Kim <kwmad.kim@samsung.com>,
        Satya Tangirala <satyat@google.com>,
        open list <linux-kernel@vger.kernel.org>
References: <1623300218-9454-1-git-send-email-cang@codeaurora.org>
 <1623300218-9454-2-git-send-email-cang@codeaurora.org>
From:   Bart Van Assche <bvanassche@acm.org>
Message-ID: <a5804465-2ad4-f122-0458-dcdd75f39310@acm.org>
Date:   Wed, 16 Jun 2021 10:50:09 -0700
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On 6/9/21 9:43 PM, Can Guo wrote:
> @@ -8784,7 +8786,7 @@ static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	enum ufs_dev_pwr_mode req_dev_pwr_mode;
>  	enum uic_link_state req_link_state;
>  
> -	hba->pm_op_in_progress = true;
> +	hba->wl_pm_op_in_progress = true;
>  	if (pm_op != UFS_SHUTDOWN_PM) {
>  		pm_lvl = pm_op == UFS_RUNTIME_PM ?
>  			 hba->rpm_lvl : hba->spm_lvl;
> @@ -8919,7 +8921,7 @@ static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  		hba->clk_gating.is_suspended = false;
>  		ufshcd_release(hba);
>  	}
> -	hba->pm_op_in_progress = false;
> +	hba->wl_pm_op_in_progress = false;
>  	return ret;
>  }

Are the __ufshcd_wl_suspend() calls serialized in any way? If not, will
the value of wl_pm_op_in_progress be incorrect if multiple kernel
threads run __ufshcd_wl_suspend() concurrently and one of the
__ufshcd_wl_suspend() instances returns earlier than the other?

Thanks,

Bart.