scsi: ufs: add quirk to fix mishandling utrlclr/utmrlclr

In the right behavior, setting the bit to '0' indicates clear and '1'
indicates no change. If host controller handles this the other way,
UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR can be used.

[mkp: typo]

Signed-off-by: Seungwon Jeon <essuuj@gmail.com>
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: "Asutosh Das (asd)" <asutoshd@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index bbad347..937355b 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -643,7 +643,24 @@ static inline void ufshcd_put_tm_slot(struct ufs_hba *hba, int slot)
  */
 static inline void ufshcd_utrl_clear(struct ufs_hba *hba, u32 pos)
 {
-	ufshcd_writel(hba, ~(1 << pos), REG_UTP_TRANSFER_REQ_LIST_CLEAR);
+	if (hba->quirks & UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR)
+		ufshcd_writel(hba, (1 << pos), REG_UTP_TRANSFER_REQ_LIST_CLEAR);
+	else
+		ufshcd_writel(hba, ~(1 << pos),
+				REG_UTP_TRANSFER_REQ_LIST_CLEAR);
+}
+
+/**
+ * ufshcd_utmrl_clear - Clear a bit in UTRMLCLR register
+ * @hba: per adapter instance
+ * @pos: position of the bit to be cleared
+ */
+static inline void ufshcd_utmrl_clear(struct ufs_hba *hba, u32 pos)
+{
+	if (hba->quirks & UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR)
+		ufshcd_writel(hba, (1 << pos), REG_UTP_TASK_REQ_LIST_CLEAR);
+	else
+		ufshcd_writel(hba, ~(1 << pos), REG_UTP_TASK_REQ_LIST_CLEAR);
 }
 
 /**
@@ -5362,7 +5379,7 @@ static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag)
 		goto out;
 
 	spin_lock_irqsave(hba->host->host_lock, flags);
-	ufshcd_writel(hba, ~(1 << tag), REG_UTP_TASK_REQ_LIST_CLEAR);
+	ufshcd_utmrl_clear(hba, tag);
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
 
 	/* poll for max. 1 sec to clear door bell register by h/w */
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 8110dcd..09c285f 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -595,6 +595,11 @@ struct ufs_hba {
 	 */
 	#define UFSHCD_QUIRK_PRDT_BYTE_GRAN			0x80
 
+	/*
+	 * Clear handling for transfer/task request list is just opposite.
+	 */
+	#define UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR		0x100
+
 	unsigned int quirks;	/* Deviations from standard UFSHCI spec. */
 
 	/* Device deviations from standard UFS device spec. */