[dpdk-stable] [PATCH] net/failsafe: fix tx sub device deactivating

[Matan Azrad]

The corrupted code couldn't recognize that all sub devices
were not ready for tx traffic when failsafe PMD was trying
to switch device because of an unreachable condition using.

Hence, the current tx sub device variable was not updated
correctly.

The fix removed the unreachable condition and adds condition
in the right place to handle non tx device ready scenario.

Fixes: ebea83f899d8 ("net/failsafe: add plug-in support")
Fixes: 598fb8aec6f6 ("net/failsafe: support device removal")

Signed-off-by: Matan Azrad <matan at mellanox.com>
Cc: stable at dpdk.org
---
 drivers/net/failsafe/failsafe_private.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Hi Gaetan
I didn't find any real scenario which cause to problematic
behavior because of the previous code.
But it may be.    

diff --git a/drivers/net/failsafe/failsafe_private.h b/drivers/net/failsafe/failsafe_private.h
index 0361cf4..dc97aec 100644
--- a/drivers/net/failsafe/failsafe_private.h
+++ b/drivers/net/failsafe/failsafe_private.h
@@ -346,9 +346,10 @@ fs_switch_dev(struct rte_eth_dev *dev,
 			PRIV(dev)->subs_tx = i;
 			break;
 		}
-	} else if (txd && txd->state < req_state) {
-		DEBUG("No device ready, deactivating tx_dev");
-		PRIV(dev)->subs_tx = PRIV(dev)->subs_tail;
+		if (i >= PRIV(dev)->subs_tail || !sdev) {
+			DEBUG("No device ready, deactivating tx_dev");
+			PRIV(dev)->subs_tx = PRIV(dev)->subs_tail;
+		}
 	} else {
 		return;
 	}
-- 
2.7.4