[dpdk-dev] [PATCH v3] net/ixgbe: fix interrupt block issue

[Qi Zhang <qi.z.zhang@intel.com>]

When handle link status change interrupt, interrupt
will be blocked until delayed handler finish, the
duration is at least 1 second, this may cause following
VF to PF mailbox traffic be blocked and sometimes PF
can't ack to VF in time before VF think it's time out.
This patch remove this limitation, during the period
after interrupt handler finish and before delayed handler
only lsc interrupt will be disabled.

Fixes: 0a45657a6794 ("pci: rework interrupt handling")

Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
---
v3:
- during the period after interrupt handler finish and before delayed handler only lsc interrupt will be disabled.

v2:
- rebase to dpdk-next-net

 drivers/net/ixgbe/ixgbe_ethdev.c | 24 ++++++++++++++----------
 drivers/net/ixgbe/ixgbe_ethdev.h |  2 ++
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
index c66f432..a05a956 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.c
+++ b/drivers/net/ixgbe/ixgbe_ethdev.c
@@ -3762,7 +3762,6 @@ ixgbe_dev_interrupt_action(struct rte_eth_dev *dev,
 		IXGBE_DEV_PRIVATE_TO_INTR(dev->data->dev_private);
 	int64_t timeout;
 	struct rte_eth_link link;
-	int intr_enable_delay = false;
 	struct ixgbe_hw *hw =
 		IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
 
@@ -3795,20 +3794,19 @@ ixgbe_dev_interrupt_action(struct rte_eth_dev *dev,
 			timeout = IXGBE_LINK_DOWN_CHECK_TIMEOUT;
 
 		ixgbe_dev_link_status_print(dev);
-
-		intr_enable_delay = true;
-	}
-
-	if (intr_enable_delay) {
+		intr->mask_original = intr->mask;
+		/* only disable lsc interrupt */
+		intr->mask &= ~IXGBE_EIMS_LSC;
 		if (rte_eal_alarm_set(timeout * 1000,
 				      ixgbe_dev_interrupt_delayed_handler, (void *)dev) < 0)
 			PMD_DRV_LOG(ERR, "Error setting alarm");
-	} else {
-		PMD_DRV_LOG(DEBUG, "enable intr immediately");
-		ixgbe_enable_intr(dev);
-		rte_intr_enable(intr_handle);
+		else
+			intr->mask = intr->mask_original;
 	}
 
+	PMD_DRV_LOG(DEBUG, "enable intr immediately");
+	ixgbe_enable_intr(dev);
+	rte_intr_enable(intr_handle);
 
 	return 0;
 }
@@ -3839,6 +3837,8 @@ ixgbe_dev_interrupt_delayed_handler(void *param)
 		IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
 	uint32_t eicr;
 
+	ixgbe_disable_intr(hw);
+
 	eicr = IXGBE_READ_REG(hw, IXGBE_EICR);
 	if (eicr & IXGBE_EICR_MAILBOX)
 		ixgbe_pf_mbx_process(dev);
@@ -3861,6 +3861,10 @@ ixgbe_dev_interrupt_delayed_handler(void *param)
 		intr->flags &= ~IXGBE_FLAG_MACSEC;
 	}
 
+	/* restore original mask */
+	intr->mask = intr->mask_original;
+	intr->mask_original = 0;
+
 	PMD_DRV_LOG(DEBUG, "enable intr in delayed handler S[%08x]", eicr);
 	ixgbe_enable_intr(dev);
 	rte_intr_enable(intr_handle);
diff --git a/drivers/net/ixgbe/ixgbe_ethdev.h b/drivers/net/ixgbe/ixgbe_ethdev.h
index 6695b68..680d5d9 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.h
+++ b/drivers/net/ixgbe/ixgbe_ethdev.h
@@ -200,6 +200,8 @@ struct ixgbe_hw_fdir_info {
 struct ixgbe_interrupt {
 	uint32_t flags;
 	uint32_t mask;
+	/*to save original mask during delayed handler */
+	uint32_t mask_original;
 };
 
 struct ixgbe_stat_mapping_registers {
-- 
2.7.4