From: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Date: Wed, 4 Jul 2018 08:14:50 +0000 (+0300)
Subject: ravb: fix invalid context bug while calling auto-negotiation by ethtool
X-Git-Tag: v4.14.67~71
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1465aba3428dc13c9f34607e80ec0b0b9f309c95;p=platform%2Fkernel%2Flinux-rpi.git

ravb: fix invalid context bug while calling auto-negotiation by ethtool

[ Upstream commit 0973a4dd79fe56a3beecfcff675ba4c01df0b0c1 ]

Since commit 35b5f6b1a82b ("PHYLIB: Locking fixes for PHY I/O
potentially sleeping") phy_start_aneg() function utilizes a mutex
to serialize changes to phy state, however the helper function is
called in atomic context.

The bug can be reproduced by running "ethtool -r" command, the bug
is reported if CONFIG_DEBUG_ATOMIC_SLEEP build option is enabled.

Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Reviewed-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index fdf30bf..4edbd64 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1131,15 +1131,10 @@ error_exit:
 
 static int ravb_nway_reset(struct net_device *ndev)
 {
-	struct ravb_private *priv = netdev_priv(ndev);
 	int error = -ENODEV;
-	unsigned long flags;
 
-	if (ndev->phydev) {
-		spin_lock_irqsave(&priv->lock, flags);
+	if (ndev->phydev)
 		error = phy_start_aneg(ndev->phydev);
-		spin_unlock_irqrestore(&priv->lock, flags);
-	}
 
 	return error;
 }