1 files changed, 51 insertions, 17 deletions

diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index 94a2b0dfb54d..a9c08321aca9 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -37,7 +37,7 @@ static unsigned int igc_tsn_new_flags(struct igc_adapter *adapter)
 {
 	unsigned int new_flags = adapter->flags & ~IGC_FLAG_TSN_ANY_ENABLED;
 
-	if (adapter->qbv_enable)
+	if (adapter->taprio_offload_enable)
 		new_flags |= IGC_FLAG_TSN_QBV_ENABLED;
 
 	if (is_any_launchtime(adapter))
@@ -114,7 +114,6 @@ static int igc_tsn_disable_offload(struct igc_adapter *adapter)
 static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
-	bool tsn_mode_reconfig = false;
 	u32 tqavctrl, baset_l, baset_h;
 	u32 sec, nsec, cycle;
 	ktime_t base_time, systim;
@@ -133,8 +132,28 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 		wr32(IGC_STQT(i), ring->start_time);
 		wr32(IGC_ENDQT(i), ring->end_time);
 
-		txqctl |= IGC_TXQCTL_STRICT_CYCLE |
-			IGC_TXQCTL_STRICT_END;
+		if (adapter->taprio_offload_enable) {
+			/* If taprio_offload_enable is set 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.
+			 *
+			 * If taprio_offload_enable is NOT true when
+			 * enabling TSN offload, the cycle should have
+			 * no external effects, but is only used internally
+			 * to adapt the base time register after a second
+			 * has passed.
+			 *
+			 * Enabling strict mode in this case would
+			 * unnecessarily prevent the transmission of
+			 * certain packets (i.e. at the boundary of a
+			 * second) and thus interfere with the launchtime
+			 * feature that promises transmission at a
+			 * certain point in time.
+			 */
+			txqctl |= IGC_TXQCTL_STRICT_CYCLE |
+				IGC_TXQCTL_STRICT_END;
+		}
 
 		if (ring->launchtime_enable)
 			txqctl |= IGC_TXQCTL_QUEUE_MODE_LAUNCHT;
@@ -228,11 +247,10 @@ skip_cbs:
 
 	tqavctrl = rd32(IGC_TQAVCTRL) & ~IGC_TQAVCTRL_FUTSCDDIS;
 
-	if (tqavctrl & IGC_TQAVCTRL_TRANSMIT_MODE_TSN)
-		tsn_mode_reconfig = true;
-
 	tqavctrl |= IGC_TQAVCTRL_TRANSMIT_MODE_TSN | IGC_TQAVCTRL_ENHANCED_QAV;
 
+	adapter->qbv_count++;
+
 	cycle = adapter->cycle_time;
 	base_time = adapter->base_time;
 
@@ -249,17 +267,29 @@ skip_cbs:
 		 * Gate Control List (GCL) is running.
 		 */
 		if ((rd32(IGC_BASET_H) || rd32(IGC_BASET_L)) &&
-		    tsn_mode_reconfig)
+		    (adapter->tc_setup_type == TC_SETUP_QDISC_TAPRIO) &&
+		    (adapter->qbv_count > 1))
 			adapter->qbv_config_change_errors++;
 	} else {
-		/* According to datasheet section 7.5.2.9.3.3, FutScdDis bit
-		 * has to be configured before the cycle time and base time.
-		 * Tx won't hang if there is a GCL is already running,
-		 * so in this case we don't need to set FutScdDis.
-		 */
-		if (igc_is_device_id_i226(hw) &&
-		    !(rd32(IGC_BASET_H) || rd32(IGC_BASET_L)))
-			tqavctrl |= IGC_TQAVCTRL_FUTSCDDIS;
+		if (igc_is_device_id_i226(hw)) {
+			ktime_t adjust_time, expires_time;
+
+		       /* According to datasheet section 7.5.2.9.3.3, FutScdDis bit
+			* has to be configured before the cycle time and base time.
+			* Tx won't hang if a GCL is already running,
+			* so in this case we don't need to set FutScdDis.
+			*/
+			if (!(rd32(IGC_BASET_H) || rd32(IGC_BASET_L)))
+				tqavctrl |= IGC_TQAVCTRL_FUTSCDDIS;
+
+			nsec = rd32(IGC_SYSTIML);
+			sec = rd32(IGC_SYSTIMH);
+			systim = ktime_set(sec, nsec);
+
+			adjust_time = adapter->base_time;
+			expires_time = ktime_sub_ns(adjust_time, systim);
+			hrtimer_start(&adapter->hrtimer, expires_time, HRTIMER_MODE_REL);
+		}
 	}
 
 	wr32(IGC_TQAVCTRL, tqavctrl);
@@ -305,7 +335,11 @@ int igc_tsn_offload_apply(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
 
-	if (netif_running(adapter->netdev) && igc_is_device_id_i225(hw)) {
+	/* Per I225/6 HW Design Section 7.5.2.1, transmit mode
+	 * cannot be changed dynamically. Require reset the adapter.
+	 */
+	if (netif_running(adapter->netdev) &&
+	    (igc_is_device_id_i225(hw) || !adapter->qbv_count)) {
 		schedule_work(&adapter->reset_task);
 		return 0;
 	}