iavf: restore MSI state on reset

BugLink: https://bugs.launchpad.net/bugs/1954931
commit 7e4dcc13965c57869684d57a1dc6dd7be589488c upstream.

If the PF experiences an FLR, the VF's MSI and MSI-X configuration will
be conveniently and silently removed in the process. When this happens,
reset recovery will appear to complete normally but no traffic will
pass. The netdev watchdog will helpfully notify everyone of this issue.

To prevent such public embarrassment, restore MSI configuration at every
reset. For normal resets, this will do no harm, but for VF resets
resulting from a PF FLR, this will keep the VF working.

Fixes: 5eae00c57f5e ("i40evf: main driver core")
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: George Kuruvinakunnel <george.kuruvinakunnel@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index fd3717ae70ab1270c294a3c8d7f436171f7b513c..4f3b025daa14fe38fec2dd15ebcde4b3246e1fc7 100644 (file)
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -2199,6 +2199,7 @@ static void iavf_reset_task(struct work_struct *work)
        }
 
        pci_set_master(adapter->pdev);
+       pci_restore_msi_state(adapter->pdev);
 
        if (i == IAVF_RESET_WAIT_COMPLETE_COUNT) {
                dev_err(&adapter->pdev->dev, "Reset never finished (%x)\n",