[PATCH net-next 3/3] i40e: trigger PF reset when re-enabling ATR via ethtool

[Tony Nguyen <anthony.l.nguyen@intel.com>]

From: Mohammad Heib <mheib@redhat.com>

Toggling flow-director-atr via ethtool private flags does not trigger a
ring reset. If ATR was disabled while fd_ena was cleared in the TX queue
HW context (e.g. after a ring reset with both ATR and ntuple off),
re-enabling ATR causes i40e_atr() to inject FDIR descriptors into a
queue where fd_ena is still 0.

Trigger a PF reset when ATR is re-enabled so that fd_ena is re-evaluated
based on the current flag state.

Signed-off-by: Mohammad Heib <mheib@redhat.com>
Tested-by: Rinitha S <sx.rinitha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_ethtool.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
index ef9d1e78c16a..79c2cdab0f51 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
@@ -5301,6 +5301,13 @@ static int i40e_set_priv_flags(struct net_device *dev, u32 flags)
 	    test_bit(I40E_FLAG_SOURCE_PRUNING_DIS, changed_flags))
 		reset_needed = BIT(__I40E_PF_RESET_REQUESTED);
 
+	/* Re-enabling ATR requires a reset to update fd_ena in the
+	 * TX queue HW context.
+	 */
+	if (test_bit(I40E_FLAG_FD_ATR_ENA, changed_flags) &&
+	    test_bit(I40E_FLAG_FD_ATR_ENA, new_flags))
+		reset_needed = BIT(__I40E_PF_RESET_REQUESTED);
+
 	/* Before we finalize any flag changes, we need to perform some
 	 * checks to ensure that the changes are supported and safe.
 	 */
-- 
2.47.1