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From:   Can Guo <cang@codeaurora.org>
To:     asutoshd@codeaurora.org, nguyenb@codeaurora.org,
        rnayak@codeaurora.org, linux-scsi@vger.kernel.org,
        kernel-team@android.com, saravanak@google.com, salyzyn@google.com,
        cang@codeaurora.org
Cc:     Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        Pedro Sousa <pedrom.sousa@synopsys.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Bean Huo <beanhuo@micron.com>,
        Tomas Winkler <tomas.winkler@intel.com>,
        Stanley Chu <stanley.chu@mediatek.com>,
        Venkat Gopalakrishnan <venkatg@codeaurora.org>,
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v4 3/7] scsi: ufs: Fix up auto hibern8 enablement
Date:   Tue, 12 Nov 2019 22:45:47 -0800
Message-Id: <1573627552-12615-4-git-send-email-cang@codeaurora.org>
In-Reply-To: <1573627552-12615-1-git-send-email-cang@codeaurora.org>
References: <1573627552-12615-1-git-send-email-cang@codeaurora.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Fix up possible unclocked register access to auto hibern8 register in
resume path and through sysfs entry. Meanwhile, enable auto hibern8
only after device is fully initialized in probe path.

Signed-off-by: Can Guo <cang@codeaurora.org>
---
 drivers/scsi/ufs/ufs-sysfs.c | 17 +++++++++++------
 drivers/scsi/ufs/ufshcd.c    | 12 ++++++------
 2 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-sysfs.c b/drivers/scsi/ufs/ufs-sysfs.c
index 969a36b..6c2f19e 100644
--- a/drivers/scsi/ufs/ufs-sysfs.c
+++ b/drivers/scsi/ufs/ufs-sysfs.c
@@ -126,13 +126,18 @@ static void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit)
 		return;
 
 	spin_lock_irqsave(hba->host->host_lock, flags);
-	if (hba->ahit == ahit)
-		goto out_unlock;
-	hba->ahit = ahit;
-	if (!pm_runtime_suspended(hba->dev))
-		ufshcd_writel(hba, hba->ahit, REG_AUTO_HIBERNATE_IDLE_TIMER);
-out_unlock:
+	if (hba->ahit != ahit)
+		hba->ahit = ahit;
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
+	if (!pm_runtime_suspended(hba->dev)) {
+		pm_runtime_get_sync(hba->dev);
+		ufshcd_hold(hba, false);
+		spin_lock_irqsave(hba->host->host_lock, flags);
+		ufshcd_writel(hba, hba->ahit, REG_AUTO_HIBERNATE_IDLE_TIMER);
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+		ufshcd_release(hba);
+		pm_runtime_put(hba->dev);
+	}
 }
 
 /* Convert Auto-Hibernate Idle Timer register value to microseconds */
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 525f8e6..f12f5a7 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6892,9 +6892,6 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
 	/* UniPro link is active now */
 	ufshcd_set_link_active(hba);
 
-	/* Enable Auto-Hibernate if configured */
-	ufshcd_auto_hibern8_enable(hba);
-
 	ret = ufshcd_verify_dev_init(hba);
 	if (ret)
 		goto out;
@@ -6945,6 +6942,9 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
 	/* set the state as operational after switching to desired gear */
 	hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
 
+	/* Enable Auto-Hibernate if configured */
+	ufshcd_auto_hibern8_enable(hba);
+
 	/*
 	 * If we are in error handling context or in power management callbacks
 	 * context, no need to scan the host
@@ -7962,12 +7962,12 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	if (hba->clk_scaling.is_allowed)
 		ufshcd_resume_clkscaling(hba);
 
-	/* Schedule clock gating in case of no access to UFS device yet */
-	ufshcd_release(hba);
-
 	/* Enable Auto-Hibernate if configured */
 	ufshcd_auto_hibern8_enable(hba);
 
+	/* Schedule clock gating in case of no access to UFS device yet */
+	ufshcd_release(hba);
+
 	goto out;
 
 set_old_link_state:
-- 
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