Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Trevor Woerner <twoerner@gmail.com>,
        Vladimir Zapolskiy <vz@mleia.com>,
        "David S. Miller" <davem@davemloft.net>
Subject: [PATCH 5.10 59/77] net: nxp: lpc_eth.c: avoid hang when bringing interface down
Date:   Mon,  1 Nov 2021 10:17:47 +0100
Message-Id: <20211101082524.058311014@linuxfoundation.org>
In-Reply-To: <20211101082511.254155853@linuxfoundation.org>
References: <20211101082511.254155853@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Trevor Woerner <twoerner@gmail.com>

commit ace19b992436a257d9a793672e57abc28fe83e2e upstream.

A hard hang is observed whenever the ethernet interface is brought
down. If the PHY is stopped before the LPC core block is reset,
the SoC will hang. Comparing lpc_eth_close() and lpc_eth_open() I
re-arranged the ordering of the functions calls in lpc_eth_close() to
reset the hardware before stopping the PHY.
Fixes: b7370112f519 ("lpc32xx: Added ethernet driver")
Signed-off-by: Trevor Woerner <twoerner@gmail.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/nxp/lpc_eth.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/nxp/lpc_eth.c
+++ b/drivers/net/ethernet/nxp/lpc_eth.c
@@ -1015,9 +1015,6 @@ static int lpc_eth_close(struct net_devi
 	napi_disable(&pldat->napi);
 	netif_stop_queue(ndev);
 
-	if (ndev->phydev)
-		phy_stop(ndev->phydev);
-
 	spin_lock_irqsave(&pldat->lock, flags);
 	__lpc_eth_reset(pldat);
 	netif_carrier_off(ndev);
@@ -1025,6 +1022,8 @@ static int lpc_eth_close(struct net_devi
 	writel(0, LPC_ENET_MAC2(pldat->net_base));
 	spin_unlock_irqrestore(&pldat->lock, flags);
 
+	if (ndev->phydev)
+		phy_stop(ndev->phydev);
 	clk_disable_unprepare(pldat->clk);
 
 	return 0;