ixgbe: fix Tx timeouts with BQL

This patch makes sure that TXDCTL.WTHRESH is set to 1 when BQL is enabled
and EITR is set to more than 100k interrupts per second to avoid Tx timeouts.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index b0b72fccb86b..68478d6dfa2d 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -2786,13 +2786,19 @@ void ixgbe_configure_tx_ring(struct ixgbe_adapter *adapter,
 
         /*
          * set WTHRESH to encourage burst writeback, it should not be set
-         * higher than 1 when ITR is 0 as it could cause false TX hangs
+         * higher than 1 when:
+         * - ITR is 0 as it could cause false TX hangs
+         * - ITR is set to > 100k int/sec and BQL is enabled
          *
          * In order to avoid issues WTHRESH + PTHRESH should always be equal
          * to or less than the number of on chip descriptors, which is
          * currently 40.
          */
+#if IS_ENABLED(CONFIG_BQL)
+        if (!ring->q_vector || (ring->q_vector->itr < IXGBE_100K_ITR))
+#else
         if (!ring->q_vector || (ring->q_vector->itr < 8))
+#endif
                 txdctl |= (1 << 16);    /* WTHRESH = 1 */
         else
                 txdctl |= (8 << 16);    /* WTHRESH = 8 */