[PATCH 4.4 17/93] bnxt_en: reverse order of TX disable and carrier off

From: Greg Kroah-Hartman
Date: Mon Mar 01 2021 - 11:25:29 EST


From: Edwin Peer <edwin.peer@xxxxxxxxxxxx>

[ Upstream commit 132e0b65dc2b8bfa9721bfce834191f24fd1d7ed ]

A TX queue can potentially immediately timeout after it is stopped
and the last TX timestamp on that queue was more than 5 seconds ago with
carrier still up. Prevent these intermittent false TX timeouts
by bringing down carrier first before calling netif_tx_disable().

Fixes: c0c050c58d84 ("bnxt_en: New Broadcom ethernet driver.")
Signed-off-by: Edwin Peer <edwin.peer@xxxxxxxxxxxx>
Signed-off-by: Michael Chan <michael.chan@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 250ecbcca019f..7444f17b9e050 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -4313,9 +4313,10 @@ static void bnxt_tx_disable(struct bnxt *bp)
txr->dev_state = BNXT_DEV_STATE_CLOSING;
}
}
+ /* Drop carrier first to prevent TX timeout */
+ netif_carrier_off(bp->dev);
/* Stop all TX queues */
netif_tx_disable(bp->dev);
- netif_carrier_off(bp->dev);
}

static void bnxt_tx_enable(struct bnxt *bp)
--
2.27.0