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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Vasundhara Volam <vasundhara-v.volam@broadcom.com>,
        Edwin Peer <edwin.peer@broadcom.com>,
        Michael Chan <michael.chan@broadcom.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 25/86] bnxt_en: Fix race when modifying pause settings.
Date:   Mon, 27 Jul 2020 16:03:59 +0200
Message-Id: <20200727134915.625690928@linuxfoundation.org>
In-Reply-To: <20200727134914.312934924@linuxfoundation.org>
References: <20200727134914.312934924@linuxfoundation.org>
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From: Vasundhara Volam <vasundhara-v.volam@broadcom.com>

[ Upstream commit 163e9ef63641a02de4c95cd921577265c52e1ce2 ]

The driver was modified to not rely on rtnl lock to protect link
settings about 2 years ago.  The pause setting was missed when
making that change.  Fix it by acquiring link_lock mutex before
calling bnxt_hwrm_set_pause().

Fixes: e2dc9b6e38fa ("bnxt_en: Don't use rtnl lock to protect link change logic in workqueue.")
Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index 047024717d654..63730e449e088 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -1392,8 +1392,11 @@ static int bnxt_set_pauseparam(struct net_device *dev,
 	if (epause->tx_pause)
 		link_info->req_flow_ctrl |= BNXT_LINK_PAUSE_TX;
 
-	if (netif_running(dev))
+	if (netif_running(dev)) {
+		mutex_lock(&bp->link_lock);
 		rc = bnxt_hwrm_set_pause(bp);
+		mutex_unlock(&bp->link_lock);
+	}
 	return rc;
 }
 
-- 
2.25.1