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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>
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        <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>, <nguyenb@codeaurora.org>,
        <bjorn.andersson@linaro.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 v2 1/2] scsi: ufs: Re-enable WriteBooster after device reset
Date:   Tue, 8 Dec 2020 21:56:34 +0800
Message-ID: <20201208135635.15326-2-stanley.chu@mediatek.com>
In-Reply-To: <20201208135635.15326-1-stanley.chu@mediatek.com>
References: <20201208135635.15326-1-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
after by ufshcd_wb_ctrl() after device reset because hba->wb_enabled
remains true.

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

Fixes: 3d17b9b5ab11 ("scsi: ufs: Add write booster feature support")
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
---
 drivers/scsi/ufs/ufshcd.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 08c8a591e6b0..36d367eb8139 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -1221,8 +1221,13 @@ 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);
+			if (ufshcd_is_wb_allowed(hba)) {
+				hba->wb_enabled = false;
+				hba->wb_buf_flush_enabled = false;
+			}
+		}
 		if (err != -EOPNOTSUPP)
 			ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);
 	}
-- 
2.18.0