target/linux/mediatek/patches-5.4/999-2711-net-fix-premature-exit-from-napi-state-polling-in-napi-disable-v2.patch

From a3eac970a1a3e2fc8cdc98acd2594e0578725ad6 Mon Sep 17 00:00:00 2001
From: Sam Shih <sam.shih@mediatek.com>
Date: Fri, 2 Jun 2023 13:06:30 +0800
Subject: [PATCH] 
 [networking][999-2711-net-fix-premature-exit-from-napi-state-polling-in-napi-disable-v2.patch]

---
 net/core/dev.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index cccd7b407..794c768e3 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6394,7 +6394,7 @@ void napi_disable(struct napi_struct *n)
 	might_sleep();
 	set_bit(NAPI_STATE_DISABLE, &n->state);
 
-	do {
+	for ( ; ; ) {
 		val = READ_ONCE(n->state);
 		if (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
 			usleep_range(20, 200);
@@ -6403,7 +6403,10 @@ void napi_disable(struct napi_struct *n)
 
 		new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
 		new &= ~(NAPIF_STATE_THREADED);
-	} while (cmpxchg(&n->state, val, new) != val);
+
+		if (cmpxchg(&n->state, val, new) == val)
+			break;
+	}
 
 	hrtimer_cancel(&n->timer);
 
-- 
2.34.1