openwrt/target/linux/generic/backport-6.1/729-07-v6.1-net-ethernet-mtk_eth_soc-remove-cpu_relax-in-mtk_pen.patch

From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: Thu, 17 Nov 2022 00:58:46 +0100
Subject: [PATCH] net: ethernet: mtk_eth_soc: remove cpu_relax in
 mtk_pending_work

Get rid of cpu_relax in mtk_pending_work routine since MTK_RESETTING is
set only in mtk_pending_work() and it runs holding rtnl lock

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -3479,11 +3479,8 @@ static void mtk_pending_work(struct work
 	rtnl_lock();
 
 	dev_dbg(eth->dev, "[%s][%d] reset\n", __func__, __LINE__);
+	set_bit(MTK_RESETTING, &eth->state);
 
-	while (test_and_set_bit_lock(MTK_RESETTING, &eth->state))
-		cpu_relax();
-
-	dev_dbg(eth->dev, "[%s][%d] mtk_stop starts\n", __func__, __LINE__);
 	/* stop all devices to make sure that dma is properly shut down */
 	for (i = 0; i < MTK_MAC_COUNT; i++) {
 		if (!eth->netdev[i])
@@ -3517,7 +3514,7 @@ static void mtk_pending_work(struct work
 
 	dev_dbg(eth->dev, "[%s][%d] reset done\n", __func__, __LINE__);
 
-	clear_bit_unlock(MTK_RESETTING, &eth->state);
+	clear_bit(MTK_RESETTING, &eth->state);
 
 	rtnl_unlock();
 }