From: AKASHI Takahiro takahiro.akashi@linaro.org
[ Upstream commit 2b4cc3d3f4d8ec42961e98568a0afeee96a943ab ]
The check introduced in the commit a5fd39464a40 ("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 #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. #3). But this definition is truely correct.
Let's fix the logic to enforce a strict validation for consecutively-opened slots.
Fixes: a5fd39464a40 ("igc: Lift TAPRIO schedule restriction") Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org Reviewed-by: Kurt Kanzenbach kurt@linutronix.de Acked-by: Vinicius Costa Gomes vinicius.gomes@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_main.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 1a0aae7b128d8..3aa0efb542aaf 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -4874,18 +4874,18 @@ 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;