From: Leon Romanovsky <leonro@mellanox.com>
Date: Sun, 16 Jun 2019 15:05:58 +0300
Subject: RDMa/hns: Don't stuck in endless timeout loop
Patch-mainline: v5.3-rc1
Git-commit: da3929218a4481fc12f9eaa30c9edb09aad5ff24
References: bsc#1104427 FATE#326416

The "end" variable is declared as unsigned and can't be negative, it
leads to the situation where timeout limit is not honored, so let's
convert logic to ensure that loop is bounded.

drivers/infiniband/hw/hns/hns_roce_hw_v1.c: In function _hns_roce_v1_clear_hem_:
drivers/infiniband/hw/hns/hns_roce_hw_v1.c:2471:12: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
 2471 |    if (end < 0) {
      |            ^

Fixes: 669cefb654cb ("RDMA/hns: Remove jiffies operation in disable interrupt context")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/hns/hns_roce_hem.h   |    2 +-
 drivers/infiniband/hw/hns/hns_roce_hw_v1.c |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/infiniband/hw/hns/hns_roce_hem.h
+++ b/drivers/infiniband/hw/hns/hns_roce_hem.h
@@ -34,8 +34,8 @@
 #ifndef _HNS_ROCE_HEM_H
 #define _HNS_ROCE_HEM_H
 
-#define HW_SYNC_TIMEOUT_MSECS		500
 #define HW_SYNC_SLEEP_TIME_INTERVAL	20
+#define HW_SYNC_TIMEOUT_MSECS           (25 * HW_SYNC_SLEEP_TIME_INTERVAL)
 #define BT_CMD_SYNC_SHIFT		31
 
 enum {
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
@@ -2505,7 +2505,7 @@ static int hns_roce_v1_clear_hem(struct
 	end = HW_SYNC_TIMEOUT_MSECS;
 	while (1) {
 		if (readl(bt_cmd) >> BT_CMD_SYNC_SHIFT) {
-			if (end < 0) {
+			if (!end) {
 				dev_err(dev, "Write bt_cmd err,hw_sync is not zero.\n");
 				spin_unlock_irqrestore(&hr_dev->bt_cmd_lock,
 					flags);