Patch "net: ena: unmask MSI-X only after device initialization is completed" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

net: ena: unmask MSI-X only after device initialization is completed

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
net-ena-unmask-msi-x-only-after-device-initialization-is-completed.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Netanel Belgazal <[email protected]>
Date: Wed, 3 Jan 2018 06:17:29 +0000
Subject: net: ena: unmask MSI-X only after device initialization is completed

From: Netanel Belgazal <[email protected]>

[ Upstream commit 7853b49ce8e0ef6364d24512b287463841d71bd3 ]

Under certain conditions MSI-X interrupt might arrive right after it was unmasked in ena_up(). There is a chance it would be processed by the driver before device ENA_FLAG_DEV_UP flag is set. In such a case the interrupt is ignored.
ENA device operates in auto-masked mode, therefore ignoring interrupt leaves it masked for good.
Moving unmask of interrupt to be the last step in ena_up().

---
 drivers/net/ethernet/amazon/ena/ena_netdev.c |   26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

@@ -1565,7 +1565,7 @@ static int ena_rss_configure(struct ena_
 
 static int ena_up_complete(struct ena_adapter *adapter)
 {
-	int rc, i;
+	int rc;
 
 	rc = ena_rss_configure(adapter);
 	if (rc)

@@ -1584,17 +1584,6 @@ static int ena_up_complete(struct ena_ad
 
 	ena_napi_enable_all(adapter);
 
-	/* Enable completion queues interrupt */
-	for (i = 0; i < adapter->num_queues; i++)
-		ena_unmask_interrupt(&adapter->tx_ring[i],
-				     &adapter->rx_ring[i]);
-
-	/* schedule napi in case we had pending packets
-	 * from the last time we disable napi
-	 */
-	for (i = 0; i < adapter->num_queues; i++)
-		napi_schedule(&adapter->ena_napi[i].napi);
-
 	return 0;
 }
 

@@ -1731,7 +1720,7 @@ create_err:
 
 static int ena_up(struct ena_adapter *adapter)
 {
-	int rc;
+	int rc, i;
 
 	netdev_dbg(adapter->netdev, "%s\n", __func__);
 

@@ -1774,6 +1763,17 @@ static int ena_up(struct ena_adapter *ad
 
 	set_bit(ENA_FLAG_DEV_UP, &adapter->flags);
 
+	/* Enable completion queues interrupt */
+	for (i = 0; i < adapter->num_queues; i++)
+		ena_unmask_interrupt(&adapter->tx_ring[i],
+				     &adapter->rx_ring[i]);
+
+	/* schedule napi in case we had pending packets
+	 * from the last time we disable napi
+	 */
+	for (i = 0; i < adapter->num_queues; i++)
+		napi_schedule(&adapter->ena_napi[i].napi);
+
 	return rc;
 
 err_up:

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/net-ena-unmask-msi-x-only-after-device-initialization-is-completed.patch