ibmveth: lost IRQ while closing/opening device leads to service loss

The order of freeing the IRQ and freeing the device in firmware
in ibmveth_close can cause the adapter to become unusable after a
subsequent ibmveth_open.  Only a reboot of the OS will make the
network device usable again. This is seen when cycling the adapter
up and down while there is network activity.

There is a window where an IRQ will be left unserviced (H_EOI will not
be called).  The solution is to make a VIO_IRQ_DISABLE h_call, free the
device with firmware, and then call free_irq.

Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ibmveth.c b/drivers/net/ibmveth.c
index 7acb3ed..2602852 100644 (file)
--- a/drivers/net/ibmveth.c
+++ b/drivers/net/ibmveth.c
@@ -677,7 +677,7 @@ static int ibmveth_close(struct net_device *netdev)
        if (!adapter->pool_config)
                netif_stop_queue(netdev);
 
-       free_irq(netdev->irq, netdev);
+       h_vio_signal(adapter->vdev->unit_address, VIO_IRQ_DISABLE);
 
        do {
                lpar_rc = h_free_logical_lan(adapter->vdev->unit_address);
@@ -689,6 +689,8 @@ static int ibmveth_close(struct net_device *netdev)
                                     lpar_rc);
        }
 
+       free_irq(netdev->irq, netdev);
+
        adapter->rx_no_buffer = *(u64*)(((char*)adapter->buffer_list_addr) + 4096 - 8);
 
        ibmveth_cleanup(adapter);