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;
From:   Bean Huo <huobean@gmail.com>
To:     alim.akhtar@samsung.com, avri.altman@wdc.com,
        asutoshd@codeaurora.org, jejb@linux.ibm.com,
        martin.petersen@oracle.com, stanley.chu@mediatek.com,
        beanhuo@micron.com, bvanassche@acm.org, tomas.winkler@intel.com,
        cang@codeaurora.org
Cc:     linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 2/3] scsi: ufs: Keep device active mode only fWriteBoosterBufferFlushDuringHibernate == 1
Date:   Tue,  8 Dec 2020 22:09:40 +0100
Message-Id: <20201208210941.2177-3-huobean@gmail.com>
In-Reply-To: <20201208210941.2177-1-huobean@gmail.com>
References: <20201208210941.2177-1-huobean@gmail.com>
Precedence: bulk

From: Bean Huo <beanhuo@micron.com>

According to the JEDEC UFS 3.1 Spec, If fWriteBoosterBufferFlushDuringHibernate
is set to one, the device flushes the WriteBooster Buffer data automatically
whenever the link enters the hibernate (HIBERN8) state. While the flushing
operation is in progress, the device should be kept in Active power mode.
Currently, we set this flag during the UFSHCD probe stage, but we didn't deal
with its programming failure. Even this failure is less likely to occur, but
still it is possible.
This patch is to add checkup of fWriteBoosterBufferFlushDuringHibernate setting,
keep the device as "active power mode" only when this flag be successfully set
to 1.

Fixes: 51dd905bd2f6 ("scsi: ufs: Fix WriteBooster flush during runtime suspend")
Signed-off-by: Bean Huo <beanhuo@micron.com>
---
 drivers/scsi/ufs/ufs.h    |  2 ++
 drivers/scsi/ufs/ufshcd.c | 20 +++++++++++++++-----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index d593edb48767..311d5f7a024d 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -530,6 +530,8 @@ struct ufs_dev_info {
 	bool f_power_on_wp_en;
 	/* Keeps information if any of the LU is power on write protected */
 	bool is_lu_power_on_wp;
+	/* Indicates if flush WB buffer during hibern8 successfully enabled */
+	bool is_hibern8_wb_flush;
 	/* Maximum number of general LU supported by the UFS device */
 	u8 max_lu_supported;
 	u8 wb_dedicated_lu;
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index f9fefb6c7ddb..f3ba46c48383 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -283,10 +283,16 @@ static inline void ufshcd_wb_config(struct ufs_hba *hba)
 		dev_err(hba->dev, "%s: Enable WB failed: %d\n", __func__, ret);
 	else
 		dev_info(hba->dev, "%s: Write Booster Configured\n", __func__);
+
 	ret = ufshcd_wb_toggle_flush_during_h8(hba, true);
-	if (ret)
+	if (ret) {
 		dev_err(hba->dev, "%s: En WB flush during H8: failed: %d\n",
 			__func__, ret);
+		hba->dev_info.is_hibern8_wb_flush = false;
+	} else {
+		hba->dev_info.is_hibern8_wb_flush = true;
+	}
+
 	ufshcd_wb_toggle_flush(hba, true);
 }
 
@@ -5444,6 +5450,7 @@ static bool ufshcd_wb_need_flush(struct ufs_hba *hba)
 
 	if (!ufshcd_is_wb_allowed(hba))
 		return false;
+
 	/*
 	 * The ufs device needs the vcc to be ON to flush.
 	 * With user-space reduction enabled, it's enough to enable flush
@@ -8535,6 +8542,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	enum ufs_pm_level pm_lvl;
 	enum ufs_dev_pwr_mode req_dev_pwr_mode;
 	enum uic_link_state req_link_state;
+	bool hibern8;
 
 	hba->pm_op_in_progress = 1;
 	if (!ufshcd_is_shutdown_pm(pm_op)) {
@@ -8594,11 +8602,13 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		 * Hibern8, keep device power mode as "active power mode"
 		 * and VCC supply.
 		 */
+		hibern8 = req_link_state == UIC_LINK_HIBERN8_STATE ||
+			(req_link_state == UIC_LINK_ACTIVE_STATE &&
+			 ufshcd_is_auto_hibern8_enabled(hba));
+
 		hba->dev_info.b_rpm_dev_flush_capable =
-			hba->auto_bkops_enabled ||
-			(((req_link_state == UIC_LINK_HIBERN8_STATE) ||
-			((req_link_state == UIC_LINK_ACTIVE_STATE) &&
-			ufshcd_is_auto_hibern8_enabled(hba))) &&
+			hba->auto_bkops_enabled || (hibern8 &&
+			hba->dev_info.is_hibern8_wb_flush &&
 			ufshcd_wb_need_flush(hba));
 	}
 
-- 
2.17.1