[PATCH] scsi: ufs: Add retry flow for failed hba enabling

[Stanley Chu]

Once hba enabling is failed, add retry mechanism and in the
meanwhile allow vendors to apply specific handlings before
the next retry. For example, vendors can do vendor-specific
host reset flow in variant function "ufshcd_vops_hce_enable_notify()".

Signed-off-by: Stanley Chu <stanley.chu at mediatek.com>
---
 drivers/scsi/ufs/ufshcd.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 8001bbfec5c0..9186ee01379a 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4328,8 +4328,10 @@ static inline void ufshcd_hba_stop(struct ufs_hba *hba)
  */
 static int ufshcd_hba_execute_hce(struct ufs_hba *hba)
 {
-	int retry;
+	int retry_outer = 3;
+	int retry_inner;
 
+start:
 	if (!ufshcd_is_hba_active(hba))
 		/* change controller state to "reset state" */
 		ufshcd_hba_stop(hba);
@@ -4355,13 +4357,17 @@ static int ufshcd_hba_execute_hce(struct ufs_hba *hba)
 	ufshcd_delay_us(hba->vps->hba_enable_delay_us, 100);
 
 	/* wait for the host controller to complete initialization */
-	retry = 50;
+	retry_inner = 50;
 	while (ufshcd_is_hba_active(hba)) {
-		if (retry) {
-			retry--;
+		if (retry_inner) {
+			retry_inner--;
 		} else {
 			dev_err(hba->dev,
 				"Controller enable failed\n");
+			if (retry_outer) {
+				retry_outer--;
+				goto start;
+			}
 			return -EIO;
 		}
 		usleep_range(1000, 1100);
-- 
2.18.0