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From:   David Christensen <drc@linux.vnet.ibm.com>
To:     netdev@vger.kernel.org,
        Siva Reddy Kallam <siva.kallam@broadcom.com>,
        Prashant Sreedharan <prashant@broadcom.com>,
        Michael Chan <mchan@broadcom.com>
Cc:     linux-kernel@vger.kernel.org,
        David Christensen <drc@linux.vnet.ibm.com>
Subject: [PATCH v2] tg3: driver sleeps indefinitely when EEH errors exceed eeh_max_freezes
Date:   Wed, 17 Jun 2020 11:51:17 -0700
Message-Id: <20200617185117.732849-1-drc@linux.vnet.ibm.com>
In-Reply-To: <20200615190119.382589-1-drc@linux.vnet.ibm.com>
References: <20200615190119.382589-1-drc@linux.vnet.ibm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

The driver function tg3_io_error_detected() calls napi_disable twice,
without an intervening napi_enable, when the number of EEH errors exceeds
eeh_max_freezes, resulting in an indefinite sleep while holding rtnl_lock.

Add check for pcierr_recovery which skips code already executed for the
"Frozen" state.

Signed-off-by: David Christensen <drc@linux.vnet.ibm.com>
---
 drivers/net/ethernet/broadcom/tg3.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 7a3b22b35238..ebff1fc0d8ce 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -18168,8 +18168,8 @@ static pci_ers_result_t tg3_io_error_detected(struct pci_dev *pdev,
 
 	rtnl_lock();
 
-	/* We probably don't have netdev yet */
-	if (!netdev || !netif_running(netdev))
+	/* Could be second call or maybe we don't have netdev yet */
+	if (!netdev || tp->pcierr_recovery || !netif_running(netdev))
 		goto done;
 
 	/* We needn't recover from permanent error */
-- 
2.18.2