[dpdk-dev] [PATCH 10/22] net/bnxt: retry irq callback deregistration

[Ajit Khaparde]

From: Lance Richardson <lance.richard...@broadcom.com>

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")
Cc: sta...@dpdk.org

Reviewed-by: Ajit Khaparde <ajit.khapa...@broadcom.com>
Signed-off-by: Lance Richardson <lance.richard...@broadcom.com>
---
 drivers/net/bnxt/bnxt_irq.c | 63 +++++++++++++++++++++++++++----------
 drivers/net/bnxt/bnxt_irq.h |  2 +-
 2 files changed, 48 insertions(+), 17 deletions(-)

diff --git a/drivers/net/bnxt/bnxt_irq.c b/drivers/net/bnxt/bnxt_irq.c
index 9ff16ddd8..42a2ff2a3 100644
--- a/drivers/net/bnxt/bnxt_irq.c
+++ b/drivers/net/bnxt/bnxt_irq.c
@@ -51,21 +51,45 @@ static void bnxt_int_handler(void *param)
                B_CP_DB_REARM(cpr, cpr->cp_raw_cons);
 }
 
-void bnxt_free_int(struct bnxt *bp)
+int bnxt_free_int(struct bnxt *bp)
 {
-       struct bnxt_irq *irq;
-
-       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;
 }
 
 void bnxt_disable_int(struct bnxt *bp)
@@ -129,13 +153,20 @@ int bnxt_setup_int(struct bnxt *bp)
 
 int bnxt_request_int(struct bnxt *bp)
 {
+       struct rte_intr_handle *intr_handle = &bp->pdev->intr_handle;
+       struct bnxt_irq *irq = bp->irq_tbl;
        int rc = 0;
 
-       struct bnxt_irq *irq = bp->irq_tbl;
+       if (!irq)
+               return 0;
 
-       rte_intr_callback_register(&bp->pdev->intr_handle, irq->handler,
-                                  (void *)bp->eth_dev);
+       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
@@ -17,7 +17,7 @@ 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);
 int bnxt_setup_int(struct bnxt *bp);
-- 
2.20.1 (Apple Git-117)