[dpdk-stable] patch 'net/bnxt: retry IRQ callback deregistration' has been queued to LTS release 18.11.3

[Kevin Traynor <ktraynor@redhat.com>]

Hi,

FYI, your patch has been queued to LTS release 18.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 09/04/19. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable-queue

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable-queue/commit/34210b2596d636be102d900ef46cd684a87daef6

Thanks.

Kevin Traynor

---
From 34210b2596d636be102d900ef46cd684a87daef6 Mon Sep 17 00:00:00 2001
From: Lance Richardson <lance.richardson@broadcom.com>
Date: Thu, 18 Jul 2019 09:06:04 +0530
Subject: [PATCH] net/bnxt: retry IRQ callback deregistration

[ upstream commit 43f78b380f89a1b4693e64d5a84a2dff801b9c9d ]

rte_intr_callback_unregister() can fail if the handler happens to
be active at the time of the call. Add logic to retry a reasonable
number of times to help ensure that the callback is unregistered
on uninit.

Fixes: 7bc8e9a227cc ("net/bnxt: support async link notification")

Signed-off-by: Lance Richardson <lance.richardson@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
---
 drivers/net/bnxt/bnxt_irq.c | 69 ++++++++++++++++++++++++++-----------
 drivers/net/bnxt/bnxt_irq.h |  2 +-
 2 files changed, 50 insertions(+), 21 deletions(-)

diff --git a/drivers/net/bnxt/bnxt_irq.c b/drivers/net/bnxt/bnxt_irq.c
index fc60839ae..9c913d2da 100644
--- a/drivers/net/bnxt/bnxt_irq.c
+++ b/drivers/net/bnxt/bnxt_irq.c
@@ -6,4 +6,5 @@
 #include <inttypes.h>
 
+#include <rte_cycles.h>
 #include <rte_malloc.h>
 
@@ -49,22 +50,43 @@ static void bnxt_int_handler(void *param)
 }
 
-void bnxt_free_int(struct bnxt *bp)
+int bnxt_free_int(struct bnxt *bp)
 {
-	struct bnxt_irq *irq;
-
-	if (bp->irq_tbl == NULL)
-		return;
-
-	irq = bp->irq_tbl;
-	if (irq) {
-		if (irq->requested) {
-			rte_intr_callback_unregister(&bp->pdev->intr_handle,
-						     irq->handler,
-						     (void *)bp->eth_dev);
-			irq->requested = 0;
+	struct rte_intr_handle *intr_handle = &bp->pdev->intr_handle;
+	struct bnxt_irq *irq = bp->irq_tbl;
+	int rc = 0;
+
+	if (!irq)
+		return 0;
+
+	if (irq->requested) {
+		int count = 0;
+
+		/*
+		 * Callback deregistration will fail with rc -EAGAIN if the
+		 * callback is currently active. Retry every 50 ms until
+		 * successful or 500 ms has elapsed.
+		 */
+		do {
+			rc = rte_intr_callback_unregister(intr_handle,
+							  irq->handler,
+							  bp->eth_dev);
+			if (rc >= 0) {
+				irq->requested = 0;
+				break;
+			}
+			rte_delay_ms(50);
+		} while (count++ < 10);
+
+		if (rc < 0) {
+			PMD_DRV_LOG(ERR, "irq cb unregister failed rc: %d\n",
+				    rc);
+			return rc;
 		}
-		rte_free((void *)bp->irq_tbl);
-		bp->irq_tbl = NULL;
 	}
+
+	rte_free(bp->irq_tbl);
+	bp->irq_tbl = NULL;
+
+	return 0;
 }
 
@@ -117,12 +139,19 @@ setup_exit:
 int bnxt_request_int(struct bnxt *bp)
 {
-	int rc = 0;
-
+	struct rte_intr_handle *intr_handle = &bp->pdev->intr_handle;
 	struct bnxt_irq *irq = bp->irq_tbl;
+	int rc = 0;
 
-	rte_intr_callback_register(&bp->pdev->intr_handle, irq->handler,
-				   (void *)bp->eth_dev);
+	if (!irq)
+		return 0;
+
+	if (!irq->requested) {
+		rc = rte_intr_callback_register(intr_handle,
+						irq->handler,
+						bp->eth_dev);
+		if (!rc)
+			irq->requested = 1;
+	}
 
-	irq->requested = 1;
 	return rc;
 }
diff --git a/drivers/net/bnxt/bnxt_irq.h b/drivers/net/bnxt/bnxt_irq.h
index 75ba2135b..460a97a09 100644
--- a/drivers/net/bnxt/bnxt_irq.h
+++ b/drivers/net/bnxt/bnxt_irq.h
@@ -18,5 +18,5 @@ struct bnxt_irq {
 
 struct bnxt;
-void bnxt_free_int(struct bnxt *bp);
+int bnxt_free_int(struct bnxt *bp);
 void bnxt_disable_int(struct bnxt *bp);
 void bnxt_enable_int(struct bnxt *bp);
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2019-08-28 14:32:34.395321045 +0100
+++ 0044-net-bnxt-retry-IRQ-callback-deregistration.patch	2019-08-28 14:32:31.701956023 +0100
@@ -1 +1 @@
-From 43f78b380f89a1b4693e64d5a84a2dff801b9c9d Mon Sep 17 00:00:00 2001
+From 34210b2596d636be102d900ef46cd684a87daef6 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 43f78b380f89a1b4693e64d5a84a2dff801b9c9d ]
+
@@ -12 +13,0 @@
-Cc: stable@dpdk.org
@@ -22 +23 @@
-index 6c4dce401..9016871a2 100644
+index fc60839ae..9c913d2da 100644