[PATCH net-next] net: ena: resolve WARN_ON when freeing IRQs

[David Arinzon <darinzon@amazon.com>]

When IRQs are freed, a WARN_ON is triggered as the
affinity notifier is not released.
This results in the below stack trace:

[  484.544586]  ? __warn+0x84/0x130
[  484.544843]  ? free_irq+0x5c/0x70
[  484.545105]  ? report_bug+0x18a/0x1a0
[  484.545390]  ? handle_bug+0x53/0x90
[  484.545664]  ? exc_invalid_op+0x14/0x70
[  484.545959]  ? asm_exc_invalid_op+0x16/0x20
[  484.546279]  ? free_irq+0x5c/0x70
[  484.546545]  ? free_irq+0x10/0x70
[  484.546807]  ena_free_io_irq+0x5f/0x70 [ena]
[  484.547138]  ena_down+0x250/0x3e0 [ena]
[  484.547435]  ena_destroy_device+0x118/0x150 [ena]
[  484.547796]  __ena_shutoff+0x5a/0xe0 [ena]
[  484.548110]  pci_device_remove+0x3b/0xb0
[  484.548412]  device_release_driver_internal+0x193/0x200
[  484.548804]  driver_detach+0x44/0x90
[  484.549084]  bus_remove_driver+0x69/0xf0
[  484.549386]  pci_unregister_driver+0x2a/0xb0
[  484.549717]  ena_cleanup+0xc/0x130 [ena]
[  484.550021]  __do_sys_delete_module.constprop.0+0x176/0x310
[  484.550438]  ? syscall_trace_enter+0xfb/0x1c0
[  484.550782]  do_syscall_64+0x5b/0x170
[  484.551067]  entry_SYSCALL_64_after_hwframe+0x76/0x7e

Adding a call to `netif_napi_set_irq` with -1 as the IRQ index,
which frees the notifier.

Fixes: de340d8206bf ("net: ena: use napi's aRFS rmap notifers")
Signed-off-by: David Arinzon <darinzon@amazon.com>
---
 drivers/net/ethernet/amazon/ena/ena_netdev.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 6aab85a7..9e007c60 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -1716,8 +1716,12 @@ static void ena_free_io_irq(struct ena_adapter *adapter)
 	int i;
 
 	for (i = ENA_IO_IRQ_FIRST_IDX; i < ENA_MAX_MSIX_VEC(io_queue_count); i++) {
+		struct ena_napi *ena_napi;
+
 		irq = &adapter->irq_tbl[i];
 		irq_set_affinity_hint(irq->vector, NULL);
+		ena_napi = (struct ena_napi *)irq->data;
+		netif_napi_set_irq(&ena_napi->napi, -1);
 		free_irq(irq->vector, irq->data);
 	}
 }
-- 
2.47.1