[PATCH AUTOSEL 5.5 392/542] staging: wfx: fix possible overflow on jiffies comparaison

[Sasha Levin]

From: Jérôme Pouiller <jerome.pouiller at silabs.com>

[ Upstream commit def39be019b6494acd3570ce6f3f11ba1c3203a3 ]

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It is recommended to use function time_*() to compare jiffies.

Signed-off-by: Jérôme Pouiller <jerome.pouiller at silabs.com>
Link: https://lore.kernel.org/r/20200115135338.14374-45-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/staging/wfx/data_tx.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/wfx/data_tx.c b/drivers/staging/wfx/data_tx.c
index b13d7341f8bba..0c6a3a1a1ddfd 100644
--- a/drivers/staging/wfx/data_tx.c
+++ b/drivers/staging/wfx/data_tx.c
@@ -282,8 +282,7 @@ void wfx_tx_policy_init(struct wfx_vif *wvif)
 static int wfx_alloc_link_id(struct wfx_vif *wvif, const u8 *mac)
 {
 	int i, ret = 0;
-	unsigned long max_inactivity = 0;
-	unsigned long now = jiffies;
+	unsigned long oldest;
 
 	spin_lock_bh(&wvif->ps_state_lock);
 	for (i = 0; i < WFX_MAX_STA_IN_AP_MODE; ++i) {
@@ -292,13 +291,10 @@ static int wfx_alloc_link_id(struct wfx_vif *wvif, const u8 *mac)
 			break;
 		} else if (wvif->link_id_db[i].status != WFX_LINK_HARD &&
 			   !wvif->wdev->tx_queue_stats.link_map_cache[i + 1]) {
-			unsigned long inactivity =
-				now - wvif->link_id_db[i].timestamp;
-
-			if (inactivity < max_inactivity)
-				continue;
-			max_inactivity = inactivity;
-			ret = i + 1;
+			if (!ret || time_after(oldest, wvif->link_id_db[i].timestamp)) {
+				oldest = wvif->link_id_db[i].timestamp;
+				ret = i + 1;
+			}
 		}
 	}
 
-- 
2.20.1