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From:   Stanley Chu <stanley.chu@mediatek.com>
To:     <linux-scsi@vger.kernel.org>, <martin.petersen@oracle.com>,
        <avri.altman@wdc.com>, <alim.akhtar@samsung.com>,
        <jejb@linux.ibm.com>
CC:     <beanhuo@micron.com>, <asutoshd@codeaurora.org>,
        <cang@codeaurora.org>, <matthias.bgg@gmail.com>,
        <bvanassche@acm.org>, <linux-mediatek@lists.infradead.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <kuohong.wang@mediatek.com>,
        <peter.wang@mediatek.com>, <chun-hung.wu@mediatek.com>,
        <andy.teng@mediatek.com>, <chaotian.jing@mediatek.com>,
        <cc.chou@mediatek.com>, <jiajie.hao@mediatek.com>,
        <alice.chao@mediatek.com>, Stanley Chu <stanley.chu@mediatek.com>
Subject: [PATCH v1] scsi: ufs: Ensure WriteBooster to be re-enabled after device reset
Date:   Tue, 8 Dec 2020 13:49:40 +0800
Message-ID: <20201208054940.1855-1-stanley.chu@mediatek.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

UFS 3.1 specification mentions that below WriteBooster flags will be
set to default value, say disabled, after power cycle or any type
of reset event. Thus we need to reset those flag variables kept
in struct hba to align the device status and ensure WriteBooster
related functions being configured properly after device reset.

Without this fix, WriteBooster will not be enabled successfully
by ufshcd_wb_ctrl() after device reset because hba->wb_enabled
remains as true.

Flags required to be reset to default values:
- fWriteBoosterEn: hba->wb_enabled
- fWriteBoosterBufferFlushEn: hba->wb_buf_flush_enabled
- fWriteBoosterBufferFlushDuringHibernate: No variable mapped

Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
---
 drivers/scsi/ufs/ufshcd.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 7a7e056a33a9..c22887bee788 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -1218,8 +1218,11 @@ static inline void ufshcd_vops_device_reset(struct ufs_hba *hba)
 	if (hba->vops && hba->vops->device_reset) {
 		int err = hba->vops->device_reset(hba);
 
-		if (!err)
+		if (!err) {
 			ufshcd_set_ufs_dev_active(hba);
+			hba->wb_enabled = false;
+			hba->wb_buf_flush_enabled = false;
+		}
 		if (err != -EOPNOTSUPP)
 			ufshcd_update_reg_hist(&hba->ufs_stats.dev_reset, err);
 	}
-- 
2.18.0