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

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

Link: https://lore.kernel.org/r/20200528011658.71590-2-alim.akhtar@samsung.comReviewed-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Seungwon Jeon <essuuj@gmail.com>
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufshcd.c

@@ -672,7 +672,11 @@ static inline int ufshcd_get_tr_ocs(struct ufshcd_lrb *lrbp)
  */
 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);
 }
 
 /**
@@ -682,7 +686,10 @@ static inline void ufshcd_utrl_clear(struct ufs_hba *hba, u32 pos)
  */
 static inline void ufshcd_utmrl_clear(struct ufs_hba *hba, u32 pos)
 {
-	ufshcd_writel(hba, ~(1 << pos), REG_UTP_TASK_REQ_LIST_CLEAR);
+	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);
 }
 
 /**

drivers/scsi/ufs/ufshcd.h

@@ -520,6 +520,11 @@ enum ufshcd_quirks {
 	 * ops (get_ufs_hci_version) to get the correct version.
 	 */
 	UFSHCD_QUIRK_BROKEN_UFS_HCI_VERSION		= 1 << 5,
+
+	/*
+	 * Clear handling for transfer/task request list is just opposite.
+	 */
+	UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR		= 1 << 6,
 };
 
 enum ufshcd_caps {