From: Nicholas Nunley nicholas.d.nunley@intel.com
[ Upstream commit 998e5166e604fd37afe94352f7b8c2d816b11049 ]
Since commit 92418fb14750 ("i40e/i40evf: Use usec value instead of reg value for ITR defines") the driver tracks the interrupt throttling intervals in single usec units, although the actual ITRN/ITR0 registers are programmed in 2 usec units. Most register programming flows in the driver correctly handle the conversion, although it is currently not applied when the registers are initialized to their default values. Most of the time this doesn't present a problem since the default values are usually immediately overwritten through the standard adaptive throttling mechanism, or updated manually by the user, but if adaptive throttling is disabled and the interval values are left alone then the incorrect value will persist.
Since the intended default interval of 50 usecs (vs. 100 usecs as programmed) performs better for most traffic workloads, this can lead to performance regressions.
This patch adds the correct conversion when writing the initial values to the ITRN registers.
Signed-off-by: Nicholas Nunley nicholas.d.nunley@intel.com Tested-by: Andrew Bowers andrewx.bowers@intel.com Signed-off-by: Jeff Kirsher jeffrey.t.kirsher@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/intel/i40e/i40e_main.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 6031223eafab..339925af0206 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -3534,14 +3534,14 @@ static void i40e_vsi_configure_msix(struct i40e_vsi *vsi) q_vector->rx.target_itr = ITR_TO_REG(vsi->rx_rings[i]->itr_setting); wr32(hw, I40E_PFINT_ITRN(I40E_RX_ITR, vector - 1), - q_vector->rx.target_itr); + q_vector->rx.target_itr >> 1); q_vector->rx.current_itr = q_vector->rx.target_itr;
q_vector->tx.next_update = jiffies + 1; q_vector->tx.target_itr = ITR_TO_REG(vsi->tx_rings[i]->itr_setting); wr32(hw, I40E_PFINT_ITRN(I40E_TX_ITR, vector - 1), - q_vector->tx.target_itr); + q_vector->tx.target_itr >> 1); q_vector->tx.current_itr = q_vector->tx.target_itr;
wr32(hw, I40E_PFINT_RATEN(vector - 1), @@ -3646,11 +3646,11 @@ static void i40e_configure_msi_and_legacy(struct i40e_vsi *vsi) /* set the ITR configuration */ q_vector->rx.next_update = jiffies + 1; q_vector->rx.target_itr = ITR_TO_REG(vsi->rx_rings[0]->itr_setting); - wr32(hw, I40E_PFINT_ITR0(I40E_RX_ITR), q_vector->rx.target_itr); + wr32(hw, I40E_PFINT_ITR0(I40E_RX_ITR), q_vector->rx.target_itr >> 1); q_vector->rx.current_itr = q_vector->rx.target_itr; q_vector->tx.next_update = jiffies + 1; q_vector->tx.target_itr = ITR_TO_REG(vsi->tx_rings[0]->itr_setting); - wr32(hw, I40E_PFINT_ITR0(I40E_TX_ITR), q_vector->tx.target_itr); + wr32(hw, I40E_PFINT_ITR0(I40E_TX_ITR), q_vector->tx.target_itr >> 1); q_vector->tx.current_itr = q_vector->tx.target_itr;
i40e_enable_misc_int_causes(pf); @@ -11396,7 +11396,7 @@ static int i40e_setup_misc_vector(struct i40e_pf *pf)
/* associate no queues to the misc vector */ wr32(hw, I40E_PFINT_LNKLST0, I40E_QUEUE_END_OF_LIST); - wr32(hw, I40E_PFINT_ITR0(I40E_RX_ITR), I40E_ITR_8K); + wr32(hw, I40E_PFINT_ITR0(I40E_RX_ITR), I40E_ITR_8K >> 1);
i40e_flush(hw);