[dpdk-stable] [PATCH v2] net/i40e: fix wrong handle when enable interrupt

[dpdk-stable] [PATCH v2] net/i40e: fix wrong handle when enable interrupt

[Qi Zhang]

In i40e_dev_interrupt_handler, when call rte_intr_enable,
the intr_handle is the copy when we registered.
According to interrupt handle framework, if the requirement
of intr_handle is changed, we need to unregister then register
a new copy. This happens on i40e driver when bind to vfio-pci,
the rte_intr_efd_enable function will modify the max_intr according
the queue number, so a new copy of intr_handle need to be registered.
Without this fix, we saw lw3fwd-power does not work due to wrong
interrupt count in vfio_irq_set when set vfio interrupt.

Fixes: 2ce7a1ed09fc ("net/i40e: localize mapping of ethdev to PCI device")

Cc: stable@dpdk.org

Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
---
v2:
- follow current design, when intr_handle is modified, unregister
  the old one and register the new one.
- there should be a patch set to fix on other devices.

 drivers/net/i40e/i40e_ethdev.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index 9c76baa..e7bbea5 100644
--- a/drivers/net/i40e/i40e_ethdev.c
+++ b/drivers/net/i40e/i40e_ethdev.c
@@ -1886,6 +1886,14 @@ i40e_dev_start(struct rte_eth_dev *dev)
 		ret = rte_intr_efd_enable(intr_handle, intr_vector);
 		if (ret)
 			return ret;
+		 /**
+		  * intr_handle may be modified in rte_intr_efd_enable
+		  * so unregster the old one and register the new one.
+		  */
+		rte_intr_callback_unregister(intr_handle,
+			i40e_dev_interrupt_handler, dev);
+		rte_intr_callback_register(intr_handle,
+			i40e_dev_interrupt_handler, dev);
 	}
 
 	if (rte_intr_dp_is_en(intr_handle) && !intr_handle->intr_vec) {
-- 
2.9.3