[PATCH 6.1 0911/1146] igc: Use strict cycles for Qbv scheduling

Greg Kroah-Hartman
2022-12-28T16:47:48Z

From: Vinicius Costa Gomes <vinicius.gomes@intel.com>

[ Upstream commit d8f45be01dd9381065a3778a579385249ed011dc ]

Configuring strict cycle mode in the controller forces more well
behaved transmissions when taprio is offloaded.

When set this strict_cycle and strict_end, transmission is not
enabled if the whole packet cannot be completed before end of
the Qbv cycle.

Fixes: 82faa9b79950 ("igc: Add support for ETF offloading")
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Aravindhan Gunasekaran <aravindhan.gunasekaran@intel.com>
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/intel/igc/igc_tsn.c | 11 ++---------
1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index 0fce22de2ab8..4a019954cadb 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -110,15 +110,8 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
wr32(IGC_STQT(i), ring->start_time);
wr32(IGC_ENDQT(i), ring->end_time);

- if (adapter->base_time) {
- /* If we have a base_time we are in "taprio"
- * mode and we need to be strict about the
- * cycles: only transmit a packet if it can be
- * completed during that cycle.
- */
- txqctl |= IGC_TXQCTL_STRICT_CYCLE |
- IGC_TXQCTL_STRICT_END;
- }
+ txqctl |= IGC_TXQCTL_STRICT_CYCLE |
+ IGC_TXQCTL_STRICT_END;

if (ring->launchtime_enable)
txqctl |= IGC_TXQCTL_QUEUE_MODE_LAUNCHT;
--
2.35.1