igc: fix the validation logic for taprio's gate list

The check introduced in the commit a5fd394 ("igc: Lift TAPRIO schedule restriction") can detect a false positive error in some corner case. For instance, tc qdisc replace ... taprio num_tc 4 ... sched-entry S 0x01 100000 # slot#1 sched-entry S 0x03 100000 # slot#2 sched-entry S 0x04 100000 # slot#3 sched-entry S 0x08 200000 # slot#4 flags 0x02 # hardware offload Here the queue#0 (the first queue) is on at the slot#1 and android-rpi#2, and off at the slot#3 and #4. Under the current logic, when the slot#4 is examined, validate_schedule() returns *false* since the enablement count for the queue#0 is two and it is already off at the previous slot (i.e. android-rpi#3). But this definition is truely correct. Let's fix the logic to enforce a strict validation for consecutively-opened slots. Fixes: a5fd394 ("igc: Lift TAPRIO schedule restriction") Signed-off-by: AKASHI Takahiro <[email protected]> Reviewed-by: Kurt Kanzenbach <[email protected]> Acked-by: Vinicius Costa Gomes <[email protected]> Tested-by: Naama Meir <[email protected]> Signed-off-by: Tony Nguyen <[email protected]>
android-risc-v · Mar 16, 2023 · 2b4cc3d · 2b4cc3d
1 parent 02c8379
commit 2b4cc3d
Showing 1 changed file with 10 additions and 10 deletions.
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -6010,18 +6010,18 @@ static bool validate_schedule(struct igc_adapter *adapter,
 		if (e->command != TC_TAPRIO_CMD_SET_GATES)
 			return false;
 
-		for (i = 0; i < adapter->num_tx_queues; i++) {
-			if (e->gate_mask & BIT(i))
+		for (i = 0; i < adapter->num_tx_queues; i++)
+			if (e->gate_mask & BIT(i)) {
 				queue_uses[i]++;
 
-			/* There are limitations: A single queue cannot be
-			 * opened and closed multiple times per cycle unless the
-			 * gate stays open. Check for it.
-			 */
-			if (queue_uses[i] > 1 &&
-			    !(prev->gate_mask & BIT(i)))
-				return false;
-		}
+				/* There are limitations: A single queue cannot
+				 * be opened and closed multiple times per cycle
+				 * unless the gate stays open. Check for it.
+				 */
+				if (queue_uses[i] > 1 &&
+				    !(prev->gate_mask & BIT(i)))
+					return false;
+			}
 	}
 
 	return true;