scsi: ufs: Re-enable WriteBooster after device reset

[ Upstream commit bd14bf0e4a084514aa62d24d2109e0f09a93822f ]

UFS 3.1 specification mentions that the WriteBooster flags listed below
will be set to their default values, i.e. disabled, after power cycle or
any type of reset event. Thus we need to reset the flag variables kept in
struct hba to align with the device status and ensure that
WriteBooster-related functions are 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

Link: https://lore.kernel.org/r/20201208135635.15326-2-stanley.chu@mediatek.com
Fixes: 3d17b9b5ab11 ("scsi: ufs: Add write booster feature support")
Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index de97971..cd51553 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -1183,8 +1183,13 @@ 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_reg_hist(&hba->ufs_stats.dev_reset, err);
        }